Attribute.GetCustomAttribute メソッド

リファレンス

定義

名前空間:: System

アセンブリ:: System.Runtime.dll

アセンブリ:: mscorlib.dll

アセンブリ:: netstandard.dll

重要

一部の情報は、リリース前に大きく変更される可能性があるプレリリースされた製品に関するものです。 Microsoft は、ここに記載されている情報について、明示または黙示を問わず、一切保証しません。

アセンブリ、モジュール、型のメンバー、またはメソッドパラメーターに適用された指定した型のカスタム属性を取得します。

オーバーロード

GetCustomAttribute(ParameterInfo, Type, Boolean)	メソッドパラメーターに適用されたカスタム属性を取得します。各パラメーターは、対象のメソッドパラメーター、検索対象のカスタム属性の型、およびそのメソッドパラメーターの先祖を検索するかどうかを指定します。
GetCustomAttribute(MemberInfo, Type, Boolean)	型のメンバーに適用されたカスタム属性を取得します。各パラメーターは、対象のメンバー、検索対象のカスタム属性の型、およびそのメンバーの先祖を検索するかどうかを指定します。
GetCustomAttribute(Assembly, Type, Boolean)	アセンブリに適用されたカスタム属性を取得します。各パラメーターは、対象のアセンブリ、検索対象のカスタム属性の型、および無視する検索オプションを指定します。
GetCustomAttribute(Module, Type, Boolean)	モジュールに適用されたカスタム属性を取得します。各パラメーターは、対象のモジュール、検索対象のカスタム属性の型、および無視する検索オプションを指定します。
GetCustomAttribute(Module, Type)	モジュールに適用されたカスタム属性を取得します。各パラメーターは、対象のモジュールと検索対象のカスタム属性の型を指定します。
GetCustomAttribute(MemberInfo, Type)	型のメンバーに適用されたカスタム属性を取得します。各パラメーターは、対象のメンバーと検索対象のカスタム属性の型を指定します。
GetCustomAttribute(Assembly, Type)	指定したアセンブリに適用されたカスタム属性を取得します。各パラメーターは、対象のアセンブリと検索対象のカスタム属性の型を指定します。
GetCustomAttribute(ParameterInfo, Type)	メソッドパラメーターに適用されたカスタム属性を取得します。各パラメーターは、対象のメソッドパラメーターと検索対象のカスタム属性の型を指定します。

GetCustomAttribute(ParameterInfo, Type, Boolean)

メソッドパラメーターに適用されたカスタム属性を取得します。各パラメーターは、対象のメソッドパラメーター、検索対象のカスタム属性の型、およびそのメソッドパラメーターの先祖を検索するかどうかを指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::ParameterInfo ^ element, Type ^ attributeType, bool inherit);

public static Attribute? GetCustomAttribute (System.Reflection.ParameterInfo element, Type attributeType, bool inherit);

public static Attribute GetCustomAttribute (System.Reflection.ParameterInfo element, Type attributeType, bool inherit);

static member GetCustomAttribute : System.Reflection.ParameterInfo * Type * bool -> Attribute

Public Shared Function GetCustomAttribute (element As ParameterInfo, attributeType As Type, inherit As Boolean) As Attribute

パラメーター

element: ParameterInfo

クラスのメンバーのパラメーターを記述する ParameterInfo クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

inherit: Boolean

true の場合は、element の先祖のカスタム属性も検索することを示します。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

AmbiguousMatchException

要求された属性が複数見つかりました。

TypeLoadException

カスタム属性の型を読み込むことはできません。

例

次のコード例では、カスタムパラメーター Attribute クラスを定義し、派生クラスのメソッドと派生クラスの基本にカスタム属性を適用します。この例では、メソッドを使用して GetCustomAttribute 属性を返す方法を示します。

// Example for the Attribute::GetCustomAttribute( ParameterInfo*, Type*, bool ) 
// method.
using namespace System;
using namespace System::Collections;
using namespace System::Reflection;

namespace NDP_UE_CPP
{
   // Define a custom parameter attribute that takes a single message argument.

   [AttributeUsage(AttributeTargets::Parameter)]
   public ref class ArgumentUsageAttribute: public Attribute
   {
   protected:

      // usageMsg is storage for the attribute message.
      String^ usageMsg;

   public:

      // This is the attribute constructor.
      ArgumentUsageAttribute( String^ UsageMsg )
      {
         this->usageMsg = UsageMsg;
      }

      property String^ Message 
      {
         // This is the Message property for the attribute.
         String^ get()
         {
            return usageMsg;
         }

         void set( String^ value )
         {
            this->usageMsg = value;
         }
      }
   };

   public ref class BaseClass
   {
   public:

      // Assign an ArgumentUsage attribute to the strArray parameter.
      // Assign a ParamArray attribute to strList.
      virtual void TestMethod( [ArgumentUsage("Must pass an array here.")]array<String^>^strArray,
                               ...array<String^>^strList ){}
   };

   public ref class DerivedClass: public BaseClass
   {
   public:

      // Assign an ArgumentUsage attributes to the strList parameter.
      virtual void TestMethod( array<String^>^strArray, [ArgumentUsage(
      "Can pass a parameter list or array here.")]array<String^>^strList ) override {}

   };

   void DisplayParameterAttributes( MethodInfo^ mInfo, array<ParameterInfo^>^pInfoArray, bool includeInherited )
   {
      Console::WriteLine( "\nParameter attribute information for method \"{0}"
      "\"\nincludes inheritance from base class: {1}.", mInfo->Name, includeInherited ? (String^)"Yes" : "No" );
      
      // This implements foreach( ParameterInfo* paramInfo in pInfoArray ).
      IEnumerator^ myEnum = pInfoArray->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         ParameterInfo^ paramInfo = safe_cast<ParameterInfo^>(myEnum->Current);

         // See if the ParamArray attribute is defined.
         bool isDef = Attribute::IsDefined( paramInfo, ParamArrayAttribute::typeid );
         if ( isDef )
                  Console::WriteLine( "\n    The ParamArray attribute is defined "
         "for \n    parameter {0} of method {1}.", paramInfo->Name, mInfo->Name );

         // See if ParamUsageAttribute is defined.  
         // If so, display a message.
         ArgumentUsageAttribute^ usageAttr = static_cast<ArgumentUsageAttribute^>(Attribute::GetCustomAttribute( paramInfo, ArgumentUsageAttribute::typeid, includeInherited ));
         if ( usageAttr != nullptr )
         {
            Console::WriteLine( "\n    The ArgumentUsage attribute is defined "
            "for \n    parameter {0} of method {1}.", paramInfo->Name, mInfo->Name );
            Console::WriteLine( "\n        The usage "
            "message for {0} is:\n        \"{1}\".", paramInfo->Name, usageAttr->Message );
         }
      }
   }

}

int main()
{
   Console::WriteLine( "This example of Attribute::GetCustomAttribute( ParameterInfo*, "
   "Type*, bool )\ngenerates the following output." );

   // Get the class type, and then get the MethodInfo object 
   // for TestMethod to access its metadata.
   Type^ clsType = NDP_UE_CPP::DerivedClass::typeid;
   MethodInfo^ mInfo = clsType->GetMethod(  "TestMethod" );

   // Iterate through the ParameterInfo array for the method parameters.
   array<ParameterInfo^>^pInfoArray = mInfo->GetParameters();
   if ( pInfoArray != nullptr )
   {
      NDP_UE_CPP::DisplayParameterAttributes( mInfo, pInfoArray, false );
      NDP_UE_CPP::DisplayParameterAttributes( mInfo, pInfoArray, true );
   }
   else
      Console::WriteLine( "The parameters information could "
   "not be retrieved for method {0}.", mInfo->Name );
}

/*
This example of Attribute::GetCustomAttribute( ParameterInfo*, Type*, bool )
generates the following output.

Parameter attribute information for method "TestMethod"
includes inheritance from base class: No.

    The ParamArray attribute is defined for
    parameter strList of method TestMethod.

    The ArgumentUsage attribute is defined for
    parameter strList of method TestMethod.

        The usage message for strList is:
        "Can pass a parameter list or array here.".

Parameter attribute information for method "TestMethod"
includes inheritance from base class: Yes.

    The ArgumentUsage attribute is defined for
    parameter strArray of method TestMethod.

        The usage message for strArray is:
        "Must pass an array here.".

    The ParamArray attribute is defined for
    parameter strList of method TestMethod.

    The ArgumentUsage attribute is defined for
    parameter strList of method TestMethod.

        The usage message for strList is:
        "Can pass a parameter list or array here.".
*/

// Example for the Attribute.GetCustomAttribute( ParameterInfo, Type, Boolean )
// method.
using System;
using System.Reflection;

namespace NDP_UE_CS
{
    // Define a custom parameter attribute that takes a single message argument.
    [AttributeUsage( AttributeTargets.Parameter )]
    public class ArgumentUsageAttribute : Attribute
    {
        // This is the attribute constructor.
        public ArgumentUsageAttribute( string UsageMsg )
        {
            this.usageMsg = UsageMsg;
        }

        // usageMsg is storage for the attribute message.
        protected string usageMsg;

        // This is the Message property for the attribute.
        public string Message
        {
            get { return usageMsg; }
            set { usageMsg = value; }
        }
    }

    public class BaseClass
    {
        // Assign an ArgumentUsage attribute to the strArray parameter.
        // Assign a ParamArray attribute to strList using the params keyword.
        public virtual void TestMethod(
            [ArgumentUsage("Must pass an array here.")]
            String[] strArray,
            params String[] strList)
        { }
    }

    public class DerivedClass : BaseClass
    {
        // Assign an ArgumentUsage attribute to the strList parameter.
        // Assign a ParamArray attribute to strList using the params keyword.
        public override void TestMethod(
            String[] strArray,
            [ArgumentUsage("Can pass a parameter list or array here.")]
            params String[] strList)
        { }
    }

    class CustomParamDemo
    {
        static void Main( )
        {
            Console.WriteLine(
                "This example of Attribute.GetCustomAttribute( Parameter" +
                "Info, Type, Boolean )\ngenerates the following output." );

            // Get the class type, and then get the MethodInfo object
            // for TestMethod to access its metadata.
            Type clsType = typeof(DerivedClass);
            MethodInfo mInfo = clsType.GetMethod("TestMethod");

            // Iterate through the ParameterInfo array for the method parameters.
            ParameterInfo[] pInfoArray = mInfo.GetParameters();
            if (pInfoArray != null)
            {
                DisplayParameterAttributes( mInfo, pInfoArray, false );
                DisplayParameterAttributes( mInfo, pInfoArray, true );
            }
            else
                Console.WriteLine("The parameters information could " +
                    "not be retrieved for method {0}.", mInfo.Name);
        }

        static void DisplayParameterAttributes( MethodInfo mInfo,
            ParameterInfo[] pInfoArray, bool includeInherited )
        {
            Console.WriteLine(
                "\nParameter attribute information for method \"" +
                "{0}\"\nincludes inheritance from base class: {1}.",
                mInfo.Name, includeInherited ? "Yes" : "No" );

            // Display the attribute information for the parameters.
            foreach( ParameterInfo paramInfo in pInfoArray )
            {
                // See if the ParamArray attribute is defined.
                bool isDef = Attribute.IsDefined( paramInfo,
                    typeof(ParamArrayAttribute));

                if( isDef )
                    Console.WriteLine(
                        "\n    The ParamArray attribute is defined " +
                        "for \n    parameter {0} of method {1}.",
                        paramInfo.Name, mInfo.Name);

                // See if ParamUsageAttribute is defined.
                // If so, display a message.
                ArgumentUsageAttribute usageAttr = (ArgumentUsageAttribute)
                    Attribute.GetCustomAttribute( paramInfo,
                        typeof(ArgumentUsageAttribute),
                        includeInherited );

                if( usageAttr != null )
                {
                    Console.WriteLine(
                        "\n    The ArgumentUsage attribute is def" +
                        "ined for \n    parameter {0} of method {1}.",
                        paramInfo.Name, mInfo.Name );

                    Console.WriteLine( "\n        The usage " +
                        "message for {0} is:\n        \"{1}\".",
                        paramInfo.Name, usageAttr.Message);
                }
            }
        }
    }
}

/*
This example of Attribute.GetCustomAttribute( ParameterInfo, Type, Boolean )
generates the following output.

Parameter attribute information for method "TestMethod"
includes inheritance from base class: No.

    The ParamArray attribute is defined for
    parameter strList of method TestMethod.

    The ArgumentUsage attribute is defined for
    parameter strList of method TestMethod.

        The usage message for strList is:
        "Can pass a parameter list or array here.".

Parameter attribute information for method "TestMethod"
includes inheritance from base class: Yes.

    The ArgumentUsage attribute is defined for
    parameter strArray of method TestMethod.

        The usage message for strArray is:
        "Must pass an array here.".

    The ParamArray attribute is defined for
    parameter strList of method TestMethod.

    The ArgumentUsage attribute is defined for
    parameter strList of method TestMethod.

        The usage message for strList is:
        "Can pass a parameter list or array here.".
*/

open System
open System.Reflection

// Define a custom parameter attribute that takes a single message argument.
[<AttributeUsage(AttributeTargets.Parameter); AllowNullLiteral>]
type ArgumentUsageAttribute(usageMsg) =
    inherit Attribute()

    // This is the Message property for the attribute.
    member val Message: string = usageMsg

type BaseClass() =
    // Assign an ArgumentUsage attribute to the strArray parameter.
    // Assign a ParamArray attribute to strList.
    abstract member TestMethod: string [] * string[] -> unit
    default _.TestMethod(
        [<ArgumentUsage "Must pass an array here.">]
        strArray,
        [<ParamArray>]
        strList) = ()

type DerivedClass() =
    inherit BaseClass()
    // Assign an ArgumentUsage attribute to the strList parameter.
    // Assign a ParamArray attribute to strList.
    override _.TestMethod(
        strArray,
        [<ArgumentUsage "Can pass a parameter list or array here."; ParamArray>]
        strList) = ()

let displayParameterAttributes (mInfo: MethodInfo) (pInfoArray: ParameterInfo []) includeInherited =
    printfn $"""
Parameter attribute information for method "{mInfo.Name}"
includes inheritance from base class: {if includeInherited then "Yes" else "No"}."""

    // Display the attribute information for the parameters.
    for paramInfo in pInfoArray do
        // See if the ParamArray attribute is defined.
        let isDef = Attribute.IsDefined(paramInfo, typeof<ParamArrayAttribute>)

        if isDef then
            printfn $"\n    The ParamArray attribute is defined for \n    parameter {paramInfo.Name} of method {mInfo.Name}."

        // See if ParamUsageAttribute is defined.
        // If so, display a message.
        let usageAttr =
            Attribute.GetCustomAttribute(paramInfo, typeof<ArgumentUsageAttribute>, includeInherited)
            :?> ArgumentUsageAttribute

        if usageAttr <> null then
            printfn $"\n    The ArgumentUsage attribute is defined for \n    parameter {paramInfo.Name} of method {mInfo.Name}." 
            printfn $"\n        The usage message for {paramInfo.Name} is:\n        \"{usageAttr.Message}\"."

printfn "This example of Attribute.GetCustomAttribute(ParameterInfo, Type, Boolean)\ngenerates the following output."

// Get the class type, and then get the MethodInfo object
// for TestMethod to access its metadata.
let clsType = typeof<DerivedClass>
let mInfo = clsType.GetMethod "TestMethod"

// Iterate through the ParameterInfo array for the method parameters.
let pInfoArray = mInfo.GetParameters()
if pInfoArray <> null then
    displayParameterAttributes mInfo pInfoArray false
    displayParameterAttributes mInfo pInfoArray true
else
    printfn $"The parameters information could not be retrieved for method {mInfo.Name}."


// This example of Attribute.GetCustomAttribute( ParameterInfo, Type, Boolean )
// generates the following output.
// 
// Parameter attribute information for method "TestMethod"
// includes inheritance from base class: No.
// 
//     The ParamArray attribute is defined for
//     parameter strList of method TestMethod.
// 
//     The ArgumentUsage attribute is defined for
//     parameter strList of method TestMethod.
// 
//         The usage message for strList is:
//         "Can pass a parameter list or array here.".
// 
// Parameter attribute information for method "TestMethod"
// includes inheritance from base class: Yes.
// 
//     The ArgumentUsage attribute is defined for
//     parameter strArray of method TestMethod.
// 
//         The usage message for strArray is:
//         "Must pass an array here.".
// 
//     The ParamArray attribute is defined for
//     parameter strList of method TestMethod.
// 
//     The ArgumentUsage attribute is defined for
//     parameter strList of method TestMethod.
// 
//         The usage message for strList is:
//         "Can pass a parameter list or array here.".

' Example for the Attribute.GetCustomAttribute( ParameterInfo, Type, Boolean ) 
' method.
Imports System.Reflection

Namespace NDP_UE_VB

    ' Define a custom parameter attribute that takes a single message argument.
    <AttributeUsage(AttributeTargets.Parameter)>  _
    Public Class ArgumentUsageAttribute
        Inherits Attribute
           
        ' This is the attribute constructor.
        Public Sub New(UsageMsg As String)
            Me.usageMsg = UsageMsg
        End Sub

        ' usageMsg is storage for the attribute message.
        Protected usageMsg As String
           
        ' This is the Message property for the attribute.
        Public Property Message() As String
            Get
                Return usageMsg
            End Get
            Set
                usageMsg = value
            End Set
        End Property
    End Class

    Public Class BaseClass
       
        ' Assign an ArgumentUsage attribute to the strArray parameter.
        ' Assign a ParamArray attribute to the strList parameter.
        Public Overridable Sub TestMethod( _
            <ArgumentUsage("Must pass an array here.")> _
            strArray() As String, _
            ParamArray strList() As String)
        End Sub
    End Class

    Public Class DerivedClass
        Inherits BaseClass
           
        ' Assign an ArgumentUsage attribute to the strList parameter.
        ' Assign a ParamArray attribute to the strList parameter.
        Public Overrides Sub TestMethod( _
            strArray() As String, _
            <ArgumentUsage("Can pass a parameter list or array here.")> _
            ParamArray strList() As String)
        End Sub
    End Class

    Class DemoClass
           
        Shared Sub DisplayParameterAttributes(mInfo As MethodInfo, _
            pInfoArray() As ParameterInfo, includeInherited As Boolean)

            Console.WriteLine( vbCrLf & _
                "Parameter attribute information for method ""{0}""" & _
                vbCrLf & "includes inheritance from the base class: {1}.", _
                mInfo.Name, IIf(includeInherited, "Yes", "No"))
              
            ' Display attribute information for the parameters.
            Dim paramInfo As ParameterInfo
            For Each paramInfo In  pInfoArray

                ' See if the ParamArray attribute is defined.
                Dim isDef As Boolean = _
                    Attribute.IsDefined(paramInfo, GetType(ParamArrayAttribute))

                If isDef Then
                    Console.WriteLine( vbCrLf & "    The " & _
                        "ParamArray attribute is defined for " & _
                        vbCrLf & "    parameter {0} of method {1}.", _
                        paramInfo.Name, mInfo.Name)
                End If
                 
                ' See if ParamUsageAttribute is defined.  
                ' If so, display a message.
                Dim usageAttr As ArgumentUsageAttribute = _
                    Attribute.GetCustomAttribute(paramInfo, _
                        GetType(ArgumentUsageAttribute), _
                        includeInherited)

                If Not (usageAttr Is Nothing) Then
                    Console.WriteLine( vbCrLf & "    The " & _
                        "ArgumentUsage attribute is defined for " & _
                        vbCrLf & "    parameter {0} of method {1}.", _
                        paramInfo.Name, mInfo.Name)
                    Console.WriteLine( vbCrLf & _
                        "        The usage message for {0} is: " & _
                        vbCrLf & "        ""{1}"".", _
                        paramInfo.Name, usageAttr.Message)
                End If
            Next paramInfo
        End Sub
       
        Public Shared Sub Main()
            Console.WriteLine( _
                "This example of Attribute.GetCustomAttribute" & _
                "( ParameterInfo, Type, Boolean )" & vbCrLf & _
                "generates the following output." )
              
            ' Get the class type, and then get the MethodInfo object 
            ' for TestMethod to access its metadata.
            Dim clsType As Type = GetType(DerivedClass)
            Dim mInfo As MethodInfo = clsType.GetMethod("TestMethod")
              
            ' Iterate through the ParameterInfo array for the method parameters.
            Dim pInfoArray As ParameterInfo() = mInfo.GetParameters()
            If Not (pInfoArray Is Nothing) Then

                DisplayParameterAttributes(mInfo, pInfoArray, False)
                DisplayParameterAttributes(mInfo, pInfoArray, True)
            Else
                Console.WriteLine( _
                    "The parameters information could " & _
                    "not be retrieved for method {0}.", mInfo.Name)
            End If
        End Sub

    End Class
End Namespace ' NDP_UE_VB

' This example of Attribute.GetCustomAttribute( ParameterInfo, Type, Boolean )
' generates the following output.
' 
' Parameter attribute information for method "TestMethod"
' includes inheritance from the base class: No.
' 
'     The ParamArray attribute is defined for
'     parameter strList of method TestMethod.
' 
'     The ArgumentUsage attribute is defined for
'     parameter strList of method TestMethod.
' 
'         The usage message for strList is:
'         "Can pass a parameter list or array here.".
' 
' Parameter attribute information for method "TestMethod"
' includes inheritance from the base class: Yes.
' 
'     The ArgumentUsage attribute is defined for
'     parameter strArray of method TestMethod.
' 
'         The usage message for strArray is:
'         "Must pass an array here.".
' 
'     The ParamArray attribute is defined for
'     parameter strList of method TestMethod.
' 
'     The ArgumentUsage attribute is defined for
'     parameter strList of method TestMethod.
' 
'         The usage message for strList is:
'         "Can pass a parameter list or array here.".

注釈

派生型のメソッドのパラメーターを表す場合 element 、戻り値には、オーバーライドされた基本メソッドの同じパラメーターに適用される継承可能なカスタム属性が含まれます。

適用対象

GetCustomAttribute(MemberInfo, Type, Boolean)

型のメンバーに適用されたカスタム属性を取得します。各パラメーターは、対象のメンバー、検索対象のカスタム属性の型、およびそのメンバーの先祖を検索するかどうかを指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::MemberInfo ^ element, Type ^ attributeType, bool inherit);

public static Attribute? GetCustomAttribute (System.Reflection.MemberInfo element, Type attributeType, bool inherit);

public static Attribute GetCustomAttribute (System.Reflection.MemberInfo element, Type attributeType, bool inherit);

static member GetCustomAttribute : System.Reflection.MemberInfo * Type * bool -> Attribute

Public Shared Function GetCustomAttribute (element As MemberInfo, attributeType As Type, inherit As Boolean) As Attribute

パラメーター

element: MemberInfo

クラスのコンストラクターメンバー、イベントメンバー、フィールドメンバー、メソッドメンバー、またはプロパティメンバーを記述する MemberInfo クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

inherit: Boolean

true の場合は、element の先祖のカスタム属性も検索することを示します。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

NotSupportedException

elementがコンストラクター、メソッド、プロパティ、イベント、型、またはフィールドではありません。

AmbiguousMatchException

要求された属性が複数見つかりました。

TypeLoadException

カスタム属性の型を読み込むことはできません。

例

次のコード例は、パラメーターとして a MemberInfo をGetCustomAttribute受け取るメソッドの使用方法を示しています。

using namespace System;
using namespace System::Reflection;

namespace IsDef4CS
{
   public ref class TestClass
   {
   public:

      // Assign the Obsolete attribute to a method.

      [Obsolete("This method is obsolete. Use Method2 instead.")]
      void Method1(){}

      void Method2(){}

   };

   ref class DemoClass
   {
   public:
      static void Main()
      {
         
         // Get the class type to access its metadata.
         Type^ clsType = TestClass::typeid;
         
         // Get the MethodInfo object for Method1.
         MethodInfo^ mInfo = clsType->GetMethod( "Method1" );
         
         // See if the Obsolete attribute is defined for this method.
         bool isDef = Attribute::IsDefined( mInfo, ObsoleteAttribute::typeid );
         
         // Display the result.
         Console::WriteLine( "The Obsolete Attribute {0} defined for {1} of class {2}.", isDef ? (String^)"is" : "is not", mInfo->Name, clsType->Name );
         
         // If it's defined, display the attribute's message.
         if ( isDef )
         {
            ObsoleteAttribute^ obsAttr = dynamic_cast<ObsoleteAttribute^>(Attribute::GetCustomAttribute( mInfo, ObsoleteAttribute::typeid ));
            if ( obsAttr != nullptr )
                        Console::WriteLine( "The message is: \"{0}\".", obsAttr->Message );
            else
                        Console::WriteLine( "The message could not be retrieved." );
         }
      }

   };

}


/*
 * Output:
 * The Obsolete Attribute is defined for Method1 of class TestClass.
 * The message is: "This method is obsolete. Use Method2 instead.".
 */

using System;
using System.Reflection;

namespace IsDef4CS
{
    public class TestClass
    {
        // Assign the Obsolete attribute to a method.
        [Obsolete("This method is obsolete. Use Method2 instead.")]
        public void Method1()
        {}
        public void Method2()
        {}
    }

    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(TestClass);
            // Get the MethodInfo object for Method1.
            MethodInfo mInfo = clsType.GetMethod("Method1");
            // See if the Obsolete attribute is defined for this method.
            bool isDef = Attribute.IsDefined(mInfo, typeof(ObsoleteAttribute));
            // Display the result.
            Console.WriteLine("The Obsolete Attribute {0} defined for {1} of class {2}.",
                isDef ? "is" : "is not", mInfo.Name, clsType.Name);
            // If it's defined, display the attribute's message.
            if (isDef)
            {
                ObsoleteAttribute obsAttr =
                                 (ObsoleteAttribute)Attribute.GetCustomAttribute(
                                                    mInfo, typeof(ObsoleteAttribute));
                if (obsAttr != null)
                    Console.WriteLine("The message is: \"{0}\".",
                        obsAttr.Message);
                else
                    Console.WriteLine("The message could not be retrieved.");
            }
        }
    }
}

/*
 * Output:
 * The Obsolete Attribute is defined for Method1 of class TestClass.
 * The message is: "This method is obsolete. Use Method2 instead.".
 */

open System

type TestClass() =
    // Assign the Obsolete attribute to a method.
    [<Obsolete "This method is obsolete. Use Method2 instead.">]
    member _.Method1() = ()
    member _.Method2() = ()

// Get the class type to access its metadata.
let clsType = typeof<TestClass>

// Get the MethodInfo object for Method1.
let mInfo = clsType.GetMethod "Method1"

// See if the Obsolete attribute is defined for this method.
let isDef = Attribute.IsDefined(mInfo, typeof<ObsoleteAttribute>)

// Display the result.
printfn $"""The Obsolete Attribute {if isDef then "is" else "is not"} defined for {mInfo.Name} of class {clsType.Name}."""

// If it's defined, display the attribute's message.
if isDef then
    let obsAttr =
        Attribute.GetCustomAttribute(mInfo, typeof<ObsoleteAttribute>)
        :?> ObsoleteAttribute
    if obsAttr <> null then
        printfn $"The message is: \"{obsAttr.Message}\"."
    else
        printfn "The message could not be retrieved."

// Output:
//  The Obsolete Attribute is defined for Method1 of class TestClass.
// The message is: "This method is obsolete. Use Method2 instead.".

Imports System.Reflection

Module DemoModule

    Public Class TestClass
        ' Assign the Obsolete attribute to a method.
        <Obsolete("This method is obsolete. Use Method2() instead.")> _
        Public Sub Method1()
        End Sub

        Public Sub Method2()
        End Sub
    End Class

    Sub Main()
        ' Get the class type to access its metadata.
        Dim clsType As Type = GetType(TestClass)
        ' Get the MethodInfo object for Method1.
        Dim mInfo As MethodInfo = clsType.GetMethod("Method1")
        ' See if the Obsolete attribute is defined for this method.
        Dim isDef As Boolean = Attribute.IsDefined(mInfo, _
            GetType(ObsoleteAttribute))
        Dim strDef As String
        If isDef = True Then
            strDef = "is"
        Else
            strDef = "is not"
        End If
        ' Display the results.
        Console.WriteLine("The Obsolete attribute {0} defined for " & _
            "method {1} of class {2}.", strDef, mInfo.Name, clsType.Name)
        ' If it's defined, display the attribute's message.
        If isDef = True Then
            Dim attr As Attribute = Attribute.GetCustomAttribute(mInfo, _
                GetType(ObsoleteAttribute))
            If Not attr Is Nothing And TypeOf attr Is ObsoleteAttribute Then
                Dim obsAttr As ObsoleteAttribute = _
                    CType(attr, ObsoleteAttribute)
                Console.WriteLine("The message is: ""{0}""", obsAttr.Message)
            Else
                Console.WriteLine("The message could not be retrieved.")
            End If
        End If
    End Sub
End Module

' Output:
' The Obsolete attribute is defined for method Method1 of class TestClass.
' The message is: "This method is obsolete. Use Method2() instead."

注釈

注意

.NET Framework バージョン 2.0 以降では、属性が新しいメタデータ形式で格納されている場合、このメソッドは型、メソッド、コンストラクターのセキュリティ属性を返します。バージョン 2.0 以降でコンパイルされたアセンブリでは、新しい形式が使用されます。以前のバージョンの.NET Frameworkでコンパイルされた動的アセンブリとアセンブリは、古い XML 形式を使用します。宣言型セキュリティ属性の出力を参照してください。

適用対象

GetCustomAttribute(Assembly, Type, Boolean)

アセンブリに適用されたカスタム属性を取得します。各パラメーターは、対象のアセンブリ、検索対象のカスタム属性の型、および無視する検索オプションを指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::Assembly ^ element, Type ^ attributeType, bool inherit);

public static Attribute? GetCustomAttribute (System.Reflection.Assembly element, Type attributeType, bool inherit);

public static Attribute GetCustomAttribute (System.Reflection.Assembly element, Type attributeType, bool inherit);

static member GetCustomAttribute : System.Reflection.Assembly * Type * bool -> Attribute

Public Shared Function GetCustomAttribute (element As Assembly, attributeType As Type, inherit As Boolean) As Attribute

パラメーター

element: Assembly

モジュールの再利用可能なコレクションを記述する Assembly クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

inherit: Boolean

このパラメーターは無視され、このメソッドの動作には影響しません。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

AmbiguousMatchException

要求された属性が複数見つかりました。

例

次のコード例は、パラメーターとして取得する GetCustomAttribute メソッドの使用方法を Assembly 示しています。

using namespace System;
using namespace System::Reflection;

// Add an AssemblyDescription attribute
[assembly:AssemblyDescription("A sample description")];
namespace IsDef1CS
{
   ref class DemoClass
   {
   public:
      static void Main()
      {
         
         // Get the class type to access its metadata.
         Type^ clsType = DemoClass::typeid;
         
         // Get the assembly object.
         Assembly^ assy = clsType->Assembly;
         
         // Store the assembly's name.
         String^ assyName = assy->GetName()->Name;
         
         //Type assyType = assy.GetType();
         // See if the Assembly Description is defined.
         bool isdef = Attribute::IsDefined( assy, AssemblyDescriptionAttribute::typeid );
         if ( isdef )
         {
            
            // Affirm that the attribute is defined.
            Console::WriteLine( "The AssemblyDescription attribute "
            "is defined for assembly {0}.", assyName );
            
            // Get the description attribute itself.
            AssemblyDescriptionAttribute^ adAttr = dynamic_cast<AssemblyDescriptionAttribute^>(Attribute::GetCustomAttribute( assy, AssemblyDescriptionAttribute::typeid ));
            
            // Display the description.
            if ( adAttr != nullptr )
                        Console::WriteLine( "The description is \"{0}\".", adAttr->Description );
            else
                        Console::WriteLine( "The description could not "
            "be retrieved." );
         }
         else
                  Console::WriteLine( "The AssemblyDescription attribute is not "
         "defined for assembly {0}.", assyName );
      }

   };

}


/*
 * Output:
 * The AssemblyDescription attributeis defined for assembly IsDef1CS.
 * The description is "A sample description".
 */

using System;
using System.Reflection;

// Add an AssemblyDescription attribute
[assembly: AssemblyDescription("A sample description")]
namespace IsDef1CS
{
    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(DemoClass);
            // Get the assembly object.
            Assembly assy = clsType.Assembly;
            // Store the assembly's name.
            String assyName = assy.GetName().Name;
            // See if the Assembly Description is defined.
            bool isdef = Attribute.IsDefined(assy,
                typeof(AssemblyDescriptionAttribute));
            if (isdef)
            {
                // Affirm that the attribute is defined.
                Console.WriteLine("The AssemblyDescription attribute " +
                    "is defined for assembly {0}.", assyName);
                // Get the description attribute itself.
                AssemblyDescriptionAttribute adAttr =
                    (AssemblyDescriptionAttribute)Attribute.GetCustomAttribute(
                    assy, typeof(AssemblyDescriptionAttribute));
                // Display the description.
                if (adAttr != null)
                    Console.WriteLine("The description is \"{0}\".",
                        adAttr.Description);
                else
                    Console.WriteLine("The description could not " +
                        "be retrieved.");
            }
            else
                Console.WriteLine("The AssemblyDescription attribute is not " +
                    "defined for assembly {0}.", assyName);
        }
    }
}

/*
 * Output:
 * The AssemblyDescription attribute is defined for assembly IsDef1CS.
 * The description is "A sample description".
 */

open System
open System.Reflection

// Add an AssemblyDescription attribute
[<assembly: AssemblyDescription "A sample description">]
do ()

type DemoClass = class end

// Get the class type to access its metadata.
let clsType = typeof<DemoClass>

// Get the assembly object.
let assembly = clsType.Assembly;

// Store the assembly's name.
let assemblyName = assembly.GetName().Name

// See if the Assembly Description is defined.
let isdef = 
    Attribute.IsDefined(assembly, typeof<AssemblyDescriptionAttribute>)

if isdef then
    // Affirm that the attribute is defined.
    printfn $"The AssemblyDescription attribute is defined for assembly {assemblyName}."
    
    // Get the description attribute itself.
    let adAttr =
        Attribute.GetCustomAttribute(assembly, typeof<AssemblyDescriptionAttribute>)
        :?> AssemblyDescriptionAttribute

    // Display the description.
    if adAttr <> null then
        printfn $"The description is \"{adAttr.Description}\"."
    else
        printfn $"The description could not be retrieved."
else
    printfn $"The AssemblyDescription attribute is not defined for assembly {assemblyName}."

// Output:
//  The AssemblyDescription attribute is defined for assembly IsDef1FS.
//  The description is "A sample description".

Imports System.Reflection

' Add an AssemblyDescription attribute.
<Assembly: AssemblyDescription("A sample description")> 

Module DemoModule
    Sub Main()
        ' Get the assembly for this module.
        Dim assy As System.Reflection.Assembly = GetType(DemoModule).Assembly
        ' Store the assembly name.
        Dim assyName As String = assy.GetName().Name
        ' See if the AssemblyDescription attribute is defined.
        If Attribute.IsDefined(assy, GetType(AssemblyDescriptionAttribute)) _
            Then
            ' Affirm that the attribute is defined. Assume the filename of
            ' this code example is "IsDef1VB".
            Console.WriteLine("The AssemblyDescription attribute is " & _
                "defined for assembly {0}.", assyName)
            ' Get the description attribute itself.
            Dim attr As Attribute = Attribute.GetCustomAttribute( _
                assy, GetType(AssemblyDescriptionAttribute))
            ' Display the description.
            If Not attr Is Nothing And _
                TypeOf attr Is AssemblyDescriptionAttribute Then
                Dim adAttr As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("The description is " & _
                    Chr(34) & "{0}" & Chr(34) & ".", adAttr.Description)
            Else
                Console.WriteLine("The description could not be retrieved.")
            End If
        Else
            Console.WriteLine("The AssemblyDescription attribute is not " & _
                              "defined for assembly {0}.", assyName)
        End If
    End Sub
End Module

' Output:
' The AssemblyDescription attribute is defined for assembly IsDef1VB.
' The description is "A sample description".

注釈

注意

.NET Framework バージョン 2.0 以降では、属性が新しいメタデータ形式で格納されている場合、このメソッドはセキュリティ属性を返します。バージョン 2.0 以降でコンパイルされたアセンブリでは、新しい形式が使用されます。以前のバージョンの.NET Frameworkでコンパイルされた動的アセンブリとアセンブリは、古い XML 形式を使用します。宣言型セキュリティ属性の出力を参照してください。

適用対象

GetCustomAttribute(Module, Type, Boolean)

モジュールに適用されたカスタム属性を取得します。各パラメーターは、対象のモジュール、検索対象のカスタム属性の型、および無視する検索オプションを指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::Module ^ element, Type ^ attributeType, bool inherit);

public static Attribute? GetCustomAttribute (System.Reflection.Module element, Type attributeType, bool inherit);

public static Attribute GetCustomAttribute (System.Reflection.Module element, Type attributeType, bool inherit);

static member GetCustomAttribute : System.Reflection.Module * Type * bool -> Attribute

Public Shared Function GetCustomAttribute (element As Module, attributeType As Type, inherit As Boolean) As Attribute

パラメーター

element: Module

移植可能な実行可能 (PE) ファイルを記述する Module クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

inherit: Boolean

このパラメーターは無視され、このメソッドの動作には影響しません。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

AmbiguousMatchException

要求された属性が複数見つかりました。

例

次のコード例は、パラメーターとして a Module をGetCustomAttribute受け取るメソッドの使用方法を示しています。

using namespace System;
using namespace System::Diagnostics;

// Add the Debuggable attribute to the module.
[module:Debuggable(true,false)];
namespace IsDef2CS
{
   ref class DemoClass
   {
   public:
      static void Main()
      {
         
         // Get the class type to access its metadata.
         Type^ clsType = DemoClass::typeid;
         
         // See if the Debuggable attribute is defined for this module.
         bool isDef = Attribute::IsDefined( clsType->Module, DebuggableAttribute::typeid );
         
         // Display the result.
         Console::WriteLine( "The Debuggable attribute {0} "
         "defined for Module {1}.", isDef ? (String^)"is" : "is not", clsType->Module->Name );
         
         // If the attribute is defined, display the JIT settings.
         if ( isDef )
         {
            
            // Retrieve the attribute itself.
            DebuggableAttribute^ dbgAttr = dynamic_cast<DebuggableAttribute^>(Attribute::GetCustomAttribute( clsType->Module, DebuggableAttribute::typeid ));
            if ( dbgAttr != nullptr )
            {
               Console::WriteLine( "JITTrackingEnabled is {0}.", dbgAttr->IsJITTrackingEnabled );
               Console::WriteLine( "JITOptimizerDisabled is {0}.", dbgAttr->IsJITOptimizerDisabled );
            }
            else
                        Console::WriteLine( "The Debuggable attribute "
            "could not be retrieved." );
         }
      }

   };

}


/*
 * Output:
 * The Debuggable attribute is defined for Module IsDef2CS.exe.
 * JITTrackingEnabled is True.
 * JITOptimizerDisabled is False.
 */

using System;
using System.Diagnostics;

// Add the Debuggable attribute to the module.
[module:Debuggable(true, false)]
namespace IsDef2CS
{
    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(DemoClass);
            // See if the Debuggable attribute is defined for this module.
            bool isDef = Attribute.IsDefined(clsType.Module,
                typeof(DebuggableAttribute));
            // Display the result.
            Console.WriteLine("The Debuggable attribute {0} " +
                "defined for Module {1}.",
                isDef ? "is" : "is not",
                clsType.Module.Name);
            // If the attribute is defined, display the JIT settings.
            if (isDef)
            {
                // Retrieve the attribute itself.
                DebuggableAttribute dbgAttr = (DebuggableAttribute)
                    Attribute.GetCustomAttribute(clsType.Module,
                    typeof(DebuggableAttribute));
                if (dbgAttr != null)
                {
                    Console.WriteLine("JITTrackingEnabled is {0}.",
                        dbgAttr.IsJITTrackingEnabled);
                    Console.WriteLine("JITOptimizerDisabled is {0}.",
                        dbgAttr.IsJITOptimizerDisabled);
                }
                else
                    Console.WriteLine("The Debuggable attribute " +
                        "could not be retrieved.");
            }
        }
    }
}

/*
 * Output:
 * The Debuggable attribute is defined for Module IsDef2CS.exe.
 * JITTrackingEnabled is True.
 * JITOptimizerDisabled is False.
 */

open System
open System.Diagnostics

// Add the Debuggable attribute to the module.
[<``module``: Debuggable(true, false)>]
do ()
    
type DemoClass = class end

// Get the class type to access its metadata.
let clsType = typeof<DemoClass>

// See if the Debuggable attribute is defined for this module.
let isDef = Attribute.IsDefined(clsType.Module, typeof<DebuggableAttribute>)

// Display the result.
printfn $"""The Debuggable attribute {if isDef then "is" else "is not"} defined for Module {clsType.Module.Name}."""

// If the attribute is defined, display the JIT settings.
if isDef then
    // Retrieve the attribute itself.
    let dbgAttr =
        Attribute.GetCustomAttribute(clsType.Module, typeof<DebuggableAttribute>)
        :?> DebuggableAttribute

    if dbgAttr <> null then
        printfn $"JITTrackingEnabled is {dbgAttr.IsJITTrackingEnabled}."
        printfn $"JITOptimizerDisabled is {dbgAttr.IsJITOptimizerDisabled}."            
    else
        printfn "The Debuggable attribute could not be retrieved."

// Output:
//  The Debuggable attribute is defined for Module IsDef2CS.exe.
//  JITTrackingEnabled is True.
//  JITOptimizerDisabled is False.

Imports System.Reflection
Imports System.Diagnostics

' Add the Debuggable attribute to the module.
<Module: Debuggable(True, False)> 

Module DemoModule
    Sub Main()
        ' Get the module type information to access its metadata.
        Dim modType As Type = GetType(DemoModule)
        ' See if the Debuggable attribute is defined.
        Dim isDef As Boolean = Attribute.IsDefined(modType.Module, _
                               GetType(DebuggableAttribute))
        Dim strDef As String
        If isDef = True Then
            strDef = "is"
        Else
            strDef = "is not"
        End If
        ' Display the result
        Console.WriteLine("The debuggable attribute {0} defined for " & _
                          "module {1}.", strDef, modType.Name)
        ' If the attribute is defined, display the JIT settings.
        If isDef = True Then
            ' Retrieve the attribute itself.
            Dim attr As Attribute = _
                Attribute.GetCustomAttribute(modType.Module, _
                GetType(DebuggableAttribute))
            If Not attr Is Nothing And TypeOf attr Is DebuggableAttribute Then
                Dim dbgAttr As DebuggableAttribute = _
                    CType(attr, DebuggableAttribute)
                Console.WriteLine("JITTrackingEnabled is {0}.", _
                    dbgAttr.IsJITTrackingEnabled.ToString())
                Console.WriteLine("JITOptimizerDisabled is {0}.", _
                    dbgAttr.IsJITOptimizerDisabled.ToString())
            Else
                Console.WriteLine("The Debuggable attribute could " & _
                                  "not be retrieved.")
            End If
        End If
    End Sub
End Module

' Output:
' The debuggable attribute is defined for module DemoModule.
' JITTrackingEnabled is True.
' JITOptimizerDisabled is False.

適用対象

GetCustomAttribute(Module, Type)

モジュールに適用されたカスタム属性を取得します。各パラメーターは、対象のモジュールと検索対象のカスタム属性の型を指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::Module ^ element, Type ^ attributeType);

public static Attribute? GetCustomAttribute (System.Reflection.Module element, Type attributeType);

public static Attribute GetCustomAttribute (System.Reflection.Module element, Type attributeType);

static member GetCustomAttribute : System.Reflection.Module * Type -> Attribute

Public Shared Function GetCustomAttribute (element As Module, attributeType As Type) As Attribute

パラメーター

element: Module

移植可能な実行可能 (PE) ファイルを記述する Module クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

AmbiguousMatchException

要求された属性が複数見つかりました。

例

次のコード例は、パラメーターとして取得ModuleするGetCustomAttributeメソッドの使用方法を示しています。

using namespace System;
using namespace System::Diagnostics;

// Add the Debuggable attribute to the module.
[module:Debuggable(true,false)];
namespace IsDef2CS
{
   ref class DemoClass
   {
   public:
      static void Main()
      {
         
         // Get the class type to access its metadata.
         Type^ clsType = DemoClass::typeid;
         
         // See if the Debuggable attribute is defined for this module.
         bool isDef = Attribute::IsDefined( clsType->Module, DebuggableAttribute::typeid );
         
         // Display the result.
         Console::WriteLine( "The Debuggable attribute {0} "
         "defined for Module {1}.", isDef ? (String^)"is" : "is not", clsType->Module->Name );
         
         // If the attribute is defined, display the JIT settings.
         if ( isDef )
         {
            
            // Retrieve the attribute itself.
            DebuggableAttribute^ dbgAttr = dynamic_cast<DebuggableAttribute^>(Attribute::GetCustomAttribute( clsType->Module, DebuggableAttribute::typeid ));
            if ( dbgAttr != nullptr )
            {
               Console::WriteLine( "JITTrackingEnabled is {0}.", dbgAttr->IsJITTrackingEnabled );
               Console::WriteLine( "JITOptimizerDisabled is {0}.", dbgAttr->IsJITOptimizerDisabled );
            }
            else
                        Console::WriteLine( "The Debuggable attribute "
            "could not be retrieved." );
         }
      }

   };

}


/*
 * Output:
 * The Debuggable attribute is defined for Module IsDef2CS.exe.
 * JITTrackingEnabled is True.
 * JITOptimizerDisabled is False.
 */

using System;
using System.Diagnostics;

// Add the Debuggable attribute to the module.
[module:Debuggable(true, false)]
namespace IsDef2CS
{
    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(DemoClass);
            // See if the Debuggable attribute is defined for this module.
            bool isDef = Attribute.IsDefined(clsType.Module,
                typeof(DebuggableAttribute));
            // Display the result.
            Console.WriteLine("The Debuggable attribute {0} " +
                "defined for Module {1}.",
                isDef ? "is" : "is not",
                clsType.Module.Name);
            // If the attribute is defined, display the JIT settings.
            if (isDef)
            {
                // Retrieve the attribute itself.
                DebuggableAttribute dbgAttr = (DebuggableAttribute)
                    Attribute.GetCustomAttribute(clsType.Module,
                    typeof(DebuggableAttribute));
                if (dbgAttr != null)
                {
                    Console.WriteLine("JITTrackingEnabled is {0}.",
                        dbgAttr.IsJITTrackingEnabled);
                    Console.WriteLine("JITOptimizerDisabled is {0}.",
                        dbgAttr.IsJITOptimizerDisabled);
                }
                else
                    Console.WriteLine("The Debuggable attribute " +
                        "could not be retrieved.");
            }
        }
    }
}

/*
 * Output:
 * The Debuggable attribute is defined for Module IsDef2CS.exe.
 * JITTrackingEnabled is True.
 * JITOptimizerDisabled is False.
 */

open System
open System.Diagnostics

// Add the Debuggable attribute to the module.
[<``module``: Debuggable(true, false)>]
do ()
    
type DemoClass = class end

// Get the class type to access its metadata.
let clsType = typeof<DemoClass>

// See if the Debuggable attribute is defined for this module.
let isDef = Attribute.IsDefined(clsType.Module, typeof<DebuggableAttribute>)

// Display the result.
printfn $"""The Debuggable attribute {if isDef then "is" else "is not"} defined for Module {clsType.Module.Name}."""

// If the attribute is defined, display the JIT settings.
if isDef then
    // Retrieve the attribute itself.
    let dbgAttr =
        Attribute.GetCustomAttribute(clsType.Module, typeof<DebuggableAttribute>)
        :?> DebuggableAttribute

    if dbgAttr <> null then
        printfn $"JITTrackingEnabled is {dbgAttr.IsJITTrackingEnabled}."
        printfn $"JITOptimizerDisabled is {dbgAttr.IsJITOptimizerDisabled}."            
    else
        printfn "The Debuggable attribute could not be retrieved."

// Output:
//  The Debuggable attribute is defined for Module IsDef2CS.exe.
//  JITTrackingEnabled is True.
//  JITOptimizerDisabled is False.

Imports System.Reflection
Imports System.Diagnostics

' Add the Debuggable attribute to the module.
<Module: Debuggable(True, False)> 

Module DemoModule
    Sub Main()
        ' Get the module type information to access its metadata.
        Dim modType As Type = GetType(DemoModule)
        ' See if the Debuggable attribute is defined.
        Dim isDef As Boolean = Attribute.IsDefined(modType.Module, _
                               GetType(DebuggableAttribute))
        Dim strDef As String
        If isDef = True Then
            strDef = "is"
        Else
            strDef = "is not"
        End If
        ' Display the result
        Console.WriteLine("The debuggable attribute {0} defined for " & _
                          "module {1}.", strDef, modType.Name)
        ' If the attribute is defined, display the JIT settings.
        If isDef = True Then
            ' Retrieve the attribute itself.
            Dim attr As Attribute = _
                Attribute.GetCustomAttribute(modType.Module, _
                GetType(DebuggableAttribute))
            If Not attr Is Nothing And TypeOf attr Is DebuggableAttribute Then
                Dim dbgAttr As DebuggableAttribute = _
                    CType(attr, DebuggableAttribute)
                Console.WriteLine("JITTrackingEnabled is {0}.", _
                    dbgAttr.IsJITTrackingEnabled.ToString())
                Console.WriteLine("JITOptimizerDisabled is {0}.", _
                    dbgAttr.IsJITOptimizerDisabled.ToString())
            Else
                Console.WriteLine("The Debuggable attribute could " & _
                                  "not be retrieved.")
            End If
        End If
    End Sub
End Module

' Output:
' The debuggable attribute is defined for module DemoModule.
' JITTrackingEnabled is True.
' JITOptimizerDisabled is False.

適用対象

GetCustomAttribute(MemberInfo, Type)

型のメンバーに適用されたカスタム属性を取得します。各パラメーターは、対象のメンバーと検索対象のカスタム属性の型を指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::MemberInfo ^ element, Type ^ attributeType);

public static Attribute? GetCustomAttribute (System.Reflection.MemberInfo element, Type attributeType);

public static Attribute GetCustomAttribute (System.Reflection.MemberInfo element, Type attributeType);

static member GetCustomAttribute : System.Reflection.MemberInfo * Type -> Attribute

Public Shared Function GetCustomAttribute (element As MemberInfo, attributeType As Type) As Attribute

パラメーター

element: MemberInfo

attributeType: Type

検索対象とするカスタム属性の型または基本型。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

NotSupportedException

elementがコンストラクター、メソッド、プロパティ、イベント、型、またはフィールドではありません。

AmbiguousMatchException

要求された属性が複数見つかりました。

TypeLoadException

カスタム属性の型を読み込むことはできません。

例

次のコード例は、パラメーターとして取得MemberInfoするGetCustomAttributeメソッドの使用方法を示しています。

using namespace System;
using namespace System::Reflection;

namespace IsDef4CS
{
   public ref class TestClass
   {
   public:

      // Assign the Obsolete attribute to a method.

      [Obsolete("This method is obsolete. Use Method2 instead.")]
      void Method1(){}

      void Method2(){}

   };

   ref class DemoClass
   {
   public:
      static void Main()
      {
         
         // Get the class type to access its metadata.
         Type^ clsType = TestClass::typeid;
         
         // Get the MethodInfo object for Method1.
         MethodInfo^ mInfo = clsType->GetMethod( "Method1" );
         
         // See if the Obsolete attribute is defined for this method.
         bool isDef = Attribute::IsDefined( mInfo, ObsoleteAttribute::typeid );
         
         // Display the result.
         Console::WriteLine( "The Obsolete Attribute {0} defined for {1} of class {2}.", isDef ? (String^)"is" : "is not", mInfo->Name, clsType->Name );
         
         // If it's defined, display the attribute's message.
         if ( isDef )
         {
            ObsoleteAttribute^ obsAttr = dynamic_cast<ObsoleteAttribute^>(Attribute::GetCustomAttribute( mInfo, ObsoleteAttribute::typeid ));
            if ( obsAttr != nullptr )
                        Console::WriteLine( "The message is: \"{0}\".", obsAttr->Message );
            else
                        Console::WriteLine( "The message could not be retrieved." );
         }
      }

   };

}


/*
 * Output:
 * The Obsolete Attribute is defined for Method1 of class TestClass.
 * The message is: "This method is obsolete. Use Method2 instead.".
 */

using System;
using System.Reflection;

namespace IsDef4CS
{
    public class TestClass
    {
        // Assign the Obsolete attribute to a method.
        [Obsolete("This method is obsolete. Use Method2 instead.")]
        public void Method1()
        {}
        public void Method2()
        {}
    }

    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(TestClass);
            // Get the MethodInfo object for Method1.
            MethodInfo mInfo = clsType.GetMethod("Method1");
            // See if the Obsolete attribute is defined for this method.
            bool isDef = Attribute.IsDefined(mInfo, typeof(ObsoleteAttribute));
            // Display the result.
            Console.WriteLine("The Obsolete Attribute {0} defined for {1} of class {2}.",
                isDef ? "is" : "is not", mInfo.Name, clsType.Name);
            // If it's defined, display the attribute's message.
            if (isDef)
            {
                ObsoleteAttribute obsAttr =
                                 (ObsoleteAttribute)Attribute.GetCustomAttribute(
                                                    mInfo, typeof(ObsoleteAttribute));
                if (obsAttr != null)
                    Console.WriteLine("The message is: \"{0}\".",
                        obsAttr.Message);
                else
                    Console.WriteLine("The message could not be retrieved.");
            }
        }
    }
}

/*
 * Output:
 * The Obsolete Attribute is defined for Method1 of class TestClass.
 * The message is: "This method is obsolete. Use Method2 instead.".
 */

open System

type TestClass() =
    // Assign the Obsolete attribute to a method.
    [<Obsolete "This method is obsolete. Use Method2 instead.">]
    member _.Method1() = ()
    member _.Method2() = ()

// Get the class type to access its metadata.
let clsType = typeof<TestClass>

// Get the MethodInfo object for Method1.
let mInfo = clsType.GetMethod "Method1"

// See if the Obsolete attribute is defined for this method.
let isDef = Attribute.IsDefined(mInfo, typeof<ObsoleteAttribute>)

// Display the result.
printfn $"""The Obsolete Attribute {if isDef then "is" else "is not"} defined for {mInfo.Name} of class {clsType.Name}."""

// If it's defined, display the attribute's message.
if isDef then
    let obsAttr =
        Attribute.GetCustomAttribute(mInfo, typeof<ObsoleteAttribute>)
        :?> ObsoleteAttribute
    if obsAttr <> null then
        printfn $"The message is: \"{obsAttr.Message}\"."
    else
        printfn "The message could not be retrieved."

// Output:
//  The Obsolete Attribute is defined for Method1 of class TestClass.
// The message is: "This method is obsolete. Use Method2 instead.".

Imports System.Reflection

Module DemoModule

    Public Class TestClass
        ' Assign the Obsolete attribute to a method.
        <Obsolete("This method is obsolete. Use Method2() instead.")> _
        Public Sub Method1()
        End Sub

        Public Sub Method2()
        End Sub
    End Class

    Sub Main()
        ' Get the class type to access its metadata.
        Dim clsType As Type = GetType(TestClass)
        ' Get the MethodInfo object for Method1.
        Dim mInfo As MethodInfo = clsType.GetMethod("Method1")
        ' See if the Obsolete attribute is defined for this method.
        Dim isDef As Boolean = Attribute.IsDefined(mInfo, _
            GetType(ObsoleteAttribute))
        Dim strDef As String
        If isDef = True Then
            strDef = "is"
        Else
            strDef = "is not"
        End If
        ' Display the results.
        Console.WriteLine("The Obsolete attribute {0} defined for " & _
            "method {1} of class {2}.", strDef, mInfo.Name, clsType.Name)
        ' If it's defined, display the attribute's message.
        If isDef = True Then
            Dim attr As Attribute = Attribute.GetCustomAttribute(mInfo, _
                GetType(ObsoleteAttribute))
            If Not attr Is Nothing And TypeOf attr Is ObsoleteAttribute Then
                Dim obsAttr As ObsoleteAttribute = _
                    CType(attr, ObsoleteAttribute)
                Console.WriteLine("The message is: ""{0}""", obsAttr.Message)
            Else
                Console.WriteLine("The message could not be retrieved.")
            End If
        End If
    End Sub
End Module

' Output:
' The Obsolete attribute is defined for method Method1 of class TestClass.
' The message is: "This method is obsolete. Use Method2() instead."

注釈

一致は、次の「戻り値」セクション Type.IsAssignableFromで説明されているのと同じ方法で決定されます。

注意

.NET Framework バージョン 2.0 以降では、属性が新しいメタデータ形式で格納されている場合、このメソッドは型、メソッド、およびコンストラクターのセキュリティ属性を返します。バージョン 2.0 以降でコンパイルされたアセンブリでは、新しい形式が使用されます。以前のバージョンの.NET Frameworkでコンパイルされた動的アセンブリとアセンブリは、古い XML 形式を使用します。宣言型セキュリティ属性の出力を参照してください。

適用対象

GetCustomAttribute(Assembly, Type)

指定したアセンブリに適用されたカスタム属性を取得します。各パラメーターは、対象のアセンブリと検索対象のカスタム属性の型を指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::Assembly ^ element, Type ^ attributeType);

public static Attribute? GetCustomAttribute (System.Reflection.Assembly element, Type attributeType);

public static Attribute GetCustomAttribute (System.Reflection.Assembly element, Type attributeType);

static member GetCustomAttribute : System.Reflection.Assembly * Type -> Attribute

Public Shared Function GetCustomAttribute (element As Assembly, attributeType As Type) As Attribute

パラメーター

element: Assembly

モジュールの再利用可能なコレクションを記述する Assembly クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

AmbiguousMatchException

要求された属性が複数見つかりました。

例

次のコード例は、パラメーターとして取得する GetCustomAttribute メソッドの使用方法を Assembly 示しています。

using namespace System;
using namespace System::Reflection;

// Add an AssemblyDescription attribute
[assembly:AssemblyDescription("A sample description")];
namespace IsDef1CS
{
   ref class DemoClass
   {
   public:
      static void Main()
      {
         
         // Get the class type to access its metadata.
         Type^ clsType = DemoClass::typeid;
         
         // Get the assembly object.
         Assembly^ assy = clsType->Assembly;
         
         // Store the assembly's name.
         String^ assyName = assy->GetName()->Name;
         
         //Type assyType = assy.GetType();
         // See if the Assembly Description is defined.
         bool isdef = Attribute::IsDefined( assy, AssemblyDescriptionAttribute::typeid );
         if ( isdef )
         {
            
            // Affirm that the attribute is defined.
            Console::WriteLine( "The AssemblyDescription attribute "
            "is defined for assembly {0}.", assyName );
            
            // Get the description attribute itself.
            AssemblyDescriptionAttribute^ adAttr = dynamic_cast<AssemblyDescriptionAttribute^>(Attribute::GetCustomAttribute( assy, AssemblyDescriptionAttribute::typeid ));
            
            // Display the description.
            if ( adAttr != nullptr )
                        Console::WriteLine( "The description is \"{0}\".", adAttr->Description );
            else
                        Console::WriteLine( "The description could not "
            "be retrieved." );
         }
         else
                  Console::WriteLine( "The AssemblyDescription attribute is not "
         "defined for assembly {0}.", assyName );
      }

   };

}


/*
 * Output:
 * The AssemblyDescription attributeis defined for assembly IsDef1CS.
 * The description is "A sample description".
 */

using System;
using System.Reflection;

// Add an AssemblyDescription attribute
[assembly: AssemblyDescription("A sample description")]
namespace IsDef1CS
{
    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(DemoClass);
            // Get the assembly object.
            Assembly assy = clsType.Assembly;
            // Store the assembly's name.
            String assyName = assy.GetName().Name;
            // See if the Assembly Description is defined.
            bool isdef = Attribute.IsDefined(assy,
                typeof(AssemblyDescriptionAttribute));
            if (isdef)
            {
                // Affirm that the attribute is defined.
                Console.WriteLine("The AssemblyDescription attribute " +
                    "is defined for assembly {0}.", assyName);
                // Get the description attribute itself.
                AssemblyDescriptionAttribute adAttr =
                    (AssemblyDescriptionAttribute)Attribute.GetCustomAttribute(
                    assy, typeof(AssemblyDescriptionAttribute));
                // Display the description.
                if (adAttr != null)
                    Console.WriteLine("The description is \"{0}\".",
                        adAttr.Description);
                else
                    Console.WriteLine("The description could not " +
                        "be retrieved.");
            }
            else
                Console.WriteLine("The AssemblyDescription attribute is not " +
                    "defined for assembly {0}.", assyName);
        }
    }
}

/*
 * Output:
 * The AssemblyDescription attribute is defined for assembly IsDef1CS.
 * The description is "A sample description".
 */

open System
open System.Reflection

// Add an AssemblyDescription attribute
[<assembly: AssemblyDescription "A sample description">]
do ()

type DemoClass = class end

// Get the class type to access its metadata.
let clsType = typeof<DemoClass>

// Get the assembly object.
let assembly = clsType.Assembly;

// Store the assembly's name.
let assemblyName = assembly.GetName().Name

// See if the Assembly Description is defined.
let isdef = 
    Attribute.IsDefined(assembly, typeof<AssemblyDescriptionAttribute>)

if isdef then
    // Affirm that the attribute is defined.
    printfn $"The AssemblyDescription attribute is defined for assembly {assemblyName}."
    
    // Get the description attribute itself.
    let adAttr =
        Attribute.GetCustomAttribute(assembly, typeof<AssemblyDescriptionAttribute>)
        :?> AssemblyDescriptionAttribute

    // Display the description.
    if adAttr <> null then
        printfn $"The description is \"{adAttr.Description}\"."
    else
        printfn $"The description could not be retrieved."
else
    printfn $"The AssemblyDescription attribute is not defined for assembly {assemblyName}."

// Output:
//  The AssemblyDescription attribute is defined for assembly IsDef1FS.
//  The description is "A sample description".

Imports System.Reflection

' Add an AssemblyDescription attribute.
<Assembly: AssemblyDescription("A sample description")> 

Module DemoModule
    Sub Main()
        ' Get the assembly for this module.
        Dim assy As System.Reflection.Assembly = GetType(DemoModule).Assembly
        ' Store the assembly name.
        Dim assyName As String = assy.GetName().Name
        ' See if the AssemblyDescription attribute is defined.
        If Attribute.IsDefined(assy, GetType(AssemblyDescriptionAttribute)) _
            Then
            ' Affirm that the attribute is defined. Assume the filename of
            ' this code example is "IsDef1VB".
            Console.WriteLine("The AssemblyDescription attribute is " & _
                "defined for assembly {0}.", assyName)
            ' Get the description attribute itself.
            Dim attr As Attribute = Attribute.GetCustomAttribute( _
                assy, GetType(AssemblyDescriptionAttribute))
            ' Display the description.
            If Not attr Is Nothing And _
                TypeOf attr Is AssemblyDescriptionAttribute Then
                Dim adAttr As AssemblyDescriptionAttribute = _
                    CType(attr, AssemblyDescriptionAttribute)
                Console.WriteLine("The description is " & _
                    Chr(34) & "{0}" & Chr(34) & ".", adAttr.Description)
            Else
                Console.WriteLine("The description could not be retrieved.")
            End If
        Else
            Console.WriteLine("The AssemblyDescription attribute is not " & _
                              "defined for assembly {0}.", assyName)
        End If
    End Sub
End Module

' Output:
' The AssemblyDescription attribute is defined for assembly IsDef1VB.
' The description is "A sample description".

注釈

複数の値が GetCustomAttributes 返されると予想される場合、または AmbiguousMatchException スローされる場合は、このメソッドを使用します。

注意

適用対象

GetCustomAttribute(ParameterInfo, Type)

メソッドパラメーターに適用されたカスタム属性を取得します。各パラメーターは、対象のメソッドパラメーターと検索対象のカスタム属性の型を指定します。

public:
 static Attribute ^ GetCustomAttribute(System::Reflection::ParameterInfo ^ element, Type ^ attributeType);

public static Attribute? GetCustomAttribute (System.Reflection.ParameterInfo element, Type attributeType);

public static Attribute GetCustomAttribute (System.Reflection.ParameterInfo element, Type attributeType);

static member GetCustomAttribute : System.Reflection.ParameterInfo * Type -> Attribute

Public Shared Function GetCustomAttribute (element As ParameterInfo, attributeType As Type) As Attribute

パラメーター

element: ParameterInfo

クラスのメンバーのパラメーターを記述する ParameterInfo クラスから派生したオブジェクト。

attributeType: Type

検索対象とするカスタム属性の型または基本型。

戻り値

Attribute

attributeType に適用される element 型の単一のカスタム属性への参照。該当する属性がない場合は null。

例外

ArgumentNullException

element または attributeType が null です。

ArgumentException

attributeType は Attribute から派生していません。

AmbiguousMatchException

要求された属性が複数見つかりました。

TypeLoadException

カスタム属性の型を読み込むことはできません。

例

次のコード例では、カスタムパラメーター Attribute クラスを定義し、派生クラスのメソッドと派生クラスのベースにカスタム属性を適用します。この例では、メソッドを GetCustomAttribute 使用して属性を返す方法を示します。

// Example for the Attribute::GetCustomAttribute( ParameterInfo*, Type* ) 
// method.
using namespace System;
using namespace System::Collections;
using namespace System::Reflection;

namespace NDP_UE_CPP
{

   // Define a custom parameter attribute that takes a single message argument.

   [AttributeUsage(AttributeTargets::Parameter)]
   public ref class ArgumentUsageAttribute: public Attribute
   {
   protected:

      // usageMsg is storage for the attribute message.
      String^ usageMsg;

   public:

      // This is the attribute constructor.
      ArgumentUsageAttribute( String^ UsageMsg )
      {
         this->usageMsg = UsageMsg;
      }


      property String^ Message 
      {
         // This is the Message property for the attribute.
         String^ get()
         {
            return usageMsg;
         }

         void set( String^ value )
         {
            this->usageMsg = value;
         }
      }
   };

   public ref class BaseClass
   {
   public:

      // Assign an ArgumentUsage attribute to the strArray parameter.
      // Assign a ParamArray attribute to strList.
      virtual void TestMethod( [ArgumentUsage("Must pass an array here.")]array<String^>^strArray,
                               ...array<String^>^strList ){}
   };

   public ref class DerivedClass: public BaseClass
   {
   public:

      // Assign an ArgumentUsage attributes to the strList parameter.
      virtual void TestMethod( array<String^>^strArray, [ArgumentUsage(
      "Can pass a parameter list or array here.")]array<String^>^strList ) override {}
   };
}

int main()
{
   Console::WriteLine( "This example of Attribute::GetCustomAttribute( Param"
   "eterInfo*, Type* )\ngenerates the following output." );

   // Get the class type, and then get the MethodInfo object 
   // for TestMethod to access its metadata.
   Type^ clsType = NDP_UE_CPP::DerivedClass::typeid;
   MethodInfo^ mInfo = clsType->GetMethod( "TestMethod" );

   // Iterate through the ParameterInfo array for the method parameters.
   array<ParameterInfo^>^pInfoArray = mInfo->GetParameters();
   if ( pInfoArray != nullptr )
   {
      // This implements foreach( ParameterInfo* paramInfo in pInfoArray ).
      IEnumerator^ myEnum = pInfoArray->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         ParameterInfo^ paramInfo = safe_cast<ParameterInfo^>(myEnum->Current);

         // See if the ParamArray attribute is defined.
         bool isDef = Attribute::IsDefined( paramInfo, ParamArrayAttribute::typeid );
         if ( isDef )
                  Console::WriteLine( "\nThe ParamArray attribute is defined for \n"
         "parameter {0} of method {1}.", paramInfo->Name, mInfo->Name );

         // See if ParamUsageAttribute is defined.  
         // If so, display a message.
         NDP_UE_CPP::ArgumentUsageAttribute^ usageAttr = static_cast<NDP_UE_CPP::ArgumentUsageAttribute^>(Attribute::GetCustomAttribute( paramInfo, NDP_UE_CPP::ArgumentUsageAttribute::typeid ));
         if ( usageAttr != nullptr )
         {
            Console::WriteLine( "\nThe ArgumentUsage attribute is defined for \n"
            "parameter {0} of method {1}.", paramInfo->Name, mInfo->Name );
            Console::WriteLine( "\n    The usage "
            "message for {0} is:\n    \"{1}\".", paramInfo->Name, usageAttr->Message );
         }
      }
   }
   else
      Console::WriteLine( "The parameters information could "
   "not be retrieved for method {0}.", mInfo->Name );
}

/*
This example of Attribute::GetCustomAttribute( ParameterInfo*, Type* )
generates the following output.

The ArgumentUsage attribute is defined for
parameter strArray of method TestMethod.

    The usage message for strArray is:
    "Must pass an array here.".

The ParamArray attribute is defined for
parameter strList of method TestMethod.

The ArgumentUsage attribute is defined for
parameter strList of method TestMethod.

    The usage message for strList is:
    "Can pass a parameter list or array here.".
*/

// Example for the Attribute.GetCustomAttribute( ParameterInfo, Type ) method.
using System;
using System.Reflection;

namespace NDP_UE_CS
{
    // Define a custom parameter attribute that takes a single message argument.
    [AttributeUsage( AttributeTargets.Parameter )]
    public class ArgumentUsageAttribute : Attribute
    {
        // This is the attribute constructor.
        public ArgumentUsageAttribute( string UsageMsg )
        {
            this.usageMsg = UsageMsg;
        }

        // usageMsg is storage for the attribute message.
        protected string usageMsg;

        // This is the Message property for the attribute.
        public string Message
        {
            get { return usageMsg; }
            set { usageMsg = value; }
        }
    }

    public class BaseClass
    {
        // Assign an ArgumentUsage attribute to the strArray parameter.
        // Assign a ParamArray attribute to strList using the params keyword.
        public virtual void TestMethod(
            [ArgumentUsage("Must pass an array here.")]
            String[] strArray,
            params String[] strList)
        { }
    }

    public class DerivedClass : BaseClass
    {
        // Assign an ArgumentUsage attribute to the strList parameter.
        // Assign a ParamArray attribute to strList using the params keyword.
        public override void TestMethod(
            String[] strArray,
            [ArgumentUsage("Can pass a parameter list or array here.")]
            params String[] strList)
        { }
    }

    class CustomParamDemo
    {
        static void Main( )
        {
            Console.WriteLine(
                "This example of Attribute.GetCustomAttribute( Param" +
                "eterInfo, Type )\ngenerates the following output." );

            // Get the class type, and then get the MethodInfo object
            // for TestMethod to access its metadata.
            Type clsType = typeof( DerivedClass );
            MethodInfo mInfo = clsType.GetMethod("TestMethod");

            // Iterate through the ParameterInfo array for the method parameters.
            ParameterInfo[] pInfoArray = mInfo.GetParameters();
            if (pInfoArray != null)
            {
                foreach( ParameterInfo paramInfo in pInfoArray )
                {
                    // See if the ParamArray attribute is defined.
                    bool isDef = Attribute.IsDefined(
                        paramInfo, typeof(ParamArrayAttribute));

                    if( isDef )
                        Console.WriteLine(
                            "\nThe ParamArray attribute is defined " +
                            "for \nparameter {0} of method {1}.",
                            paramInfo.Name, mInfo.Name);

                    // See if ParamUsageAttribute is defined.
                    // If so, display a message.
                    ArgumentUsageAttribute usageAttr = (ArgumentUsageAttribute)
                        Attribute.GetCustomAttribute(
                            paramInfo, typeof(ArgumentUsageAttribute) );

                    if( usageAttr != null )
                    {
                        Console.WriteLine(
                            "\nThe ArgumentUsage attribute is defined " +
                            "for \nparameter {0} of method {1}.",
                            paramInfo.Name, mInfo.Name );

                        Console.WriteLine( "\n    The usage " +
                            "message for {0} is:\n    \"{1}\".",
                            paramInfo.Name, usageAttr.Message);
                    }
                }
            }
            else
                Console.WriteLine(
                    "The parameters information could not " +
                    "be retrieved for method {0}.", mInfo.Name);
        }
    }
}

/*
This example of Attribute.GetCustomAttribute( ParameterInfo, Type )
generates the following output.

The ArgumentUsage attribute is defined for
parameter strArray of method TestMethod.

    The usage message for strArray is:
    "Must pass an array here.".

The ParamArray attribute is defined for
parameter strList of method TestMethod.

The ArgumentUsage attribute is defined for
parameter strList of method TestMethod.

    The usage message for strList is:
    "Can pass a parameter list or array here.".
*/

open System
open System.Reflection

// Define a custom parameter attribute that takes a single message argument.
[<AttributeUsage(AttributeTargets.Parameter); AllowNullLiteral>]
type ArgumentUsageAttribute(usageMsg) =
    inherit Attribute()
    
    // This is the Message property for the attribute.
    member val Message = usageMsg with get, set

type BaseClass() =
    // Assign an ArgumentUsage attribute to the strArray parameter.
    // Assign a ParamArray attribute to strList.
    abstract member TestMethod: strArray: string[] * strList: string[] -> unit
    default _.TestMethod([<ArgumentUsage("Must pass an array here.")>] strArray, [<ParamArray>] strList) = ()

type DerivedClass() =
    inherit BaseClass()
    
    // Assign an ArgumentUsage attribute to the strList parameter.
    // Assign a ParamArray attribute to strList.
    override _.TestMethod(
        strArray,
        [<ArgumentUsage "Can pass a parameter list or array here."; ParamArray>] 
        strList) = ()

printfn "This example of Attribute.GetCustomAttribute( ParameterInfo, Type )\ngenerates the following output."

// Get the class type, and then get the MethodInfo object
// for TestMethod to access its metadata.
let clsType = typeof<DerivedClass>
let mInfo = clsType.GetMethod "TestMethod"

// Iterate through the ParameterInfo array for the method parameters.
let pInfoArray = mInfo.GetParameters()
if pInfoArray <> null then
    for paramInfo in pInfoArray do
        // See if the ParamArray attribute is defined.
        let isDef = Attribute.IsDefined(paramInfo, typeof<ParamArrayAttribute>)

        if isDef then
            printfn $"\nThe ParamArray attribute is defined for \nparameter {paramInfo.Name} of method {mInfo.Name}."

        // See if ParamUsageAttribute is defined.
        // If so, display a message.
        let usageAttr =
            Attribute.GetCustomAttribute(paramInfo, typeof<ArgumentUsageAttribute>)
            :?> ArgumentUsageAttribute

        if usageAttr <> null then
            printfn $"\nThe ArgumentUsage attribute is defined for \nparameter {paramInfo.Name} of method {mInfo.Name}."
            printfn $"\n    The usage message for {paramInfo.Name} is:\n    \"{usageAttr.Message}\"."   
else
    printfn $"The parameters information could not be retrieved for method {mInfo.Name}."


// This example of Attribute.GetCustomAttribute(ParameterInfo, Type)
// generates the following output:
// The ArgumentUsage attribute is defined for
// parameter strArray of method TestMethod.
//
//     The usage message for strArray is:
//     "Must pass an array here.".
//
// The ParamArray attribute is defined for
// parameter strList of method TestMethod.
//
// The ArgumentUsage attribute is defined for
// parameter strList of method TestMethod.
//
//     The usage message for strList is:
//     "Can pass a parameter list or array here.".

' Example for the Attribute.GetCustomAttribute( ParameterInfo, Type ) method.
Imports System.Reflection

Namespace NDP_UE_VB

    ' Define a custom parameter attribute that takes a single message argument.
    <AttributeUsage(AttributeTargets.Parameter)>  _
    Public Class ArgumentUsageAttribute
        Inherits Attribute
           
        ' This is the attribute constructor.
        Public Sub New(UsageMsg As String)
            Me.usageMsg = UsageMsg
        End Sub

        ' usageMsg is storage for the attribute message.
        Protected usageMsg As String
           
        ' This is the Message property for the attribute.
        Public Property Message() As String
            Get
                Return usageMsg
            End Get
            Set
                usageMsg = value
            End Set
        End Property
    End Class

    Public Class BaseClass
       
        ' Assign an ArgumentUsage attribute to the strArray parameter.
        ' Assign a ParamArray attribute to strList using the ParamArray keyword.
        Public Overridable Sub TestMethod( _
            <ArgumentUsage("Must pass an array here.")> _
            strArray() As String, _
            ParamArray strList() As String)
        End Sub
    End Class

    Public Class DerivedClass
        Inherits BaseClass
           
        ' Assign an ArgumentUsage attribute to the strList parameter.
        ' Assign a ParamArray attribute to strList using the ParamArray keyword.
        Public Overrides Sub TestMethod( _
            strArray() As String, _
            <ArgumentUsage("Can pass a parameter list or array here.")> _
            ParamArray strList() As String)
        End Sub
    End Class

    Module CustomParamDemo
       
        Sub Main()
            Console.WriteLine( _
                "This example of Attribute.GetCustomAttribute" & _
                "( ParameterInfo, Type )" & vbCrLf & _
                "generates the following output.")
              
            ' Get the class type, and then get the MethodInfo object 
            ' for TestMethod to access its metadata.
            Dim clsType As Type = GetType(DerivedClass)
            Dim mInfo As MethodInfo = clsType.GetMethod("TestMethod")
              
            ' Iterate through the ParameterInfo array for the method parameters.
            Dim pInfoArray As ParameterInfo() = mInfo.GetParameters()
            If Not (pInfoArray Is Nothing) Then
                Dim paramInfo As ParameterInfo
                For Each paramInfo In  pInfoArray

                    ' See if the ParamArray attribute is defined.
                    Dim isDef As Boolean = _
                        Attribute.IsDefined(paramInfo, _
                            GetType(ParamArrayAttribute))

                    If isDef Then
                        Console.WriteLine( vbCrLf & _
                            "The ParamArray attribute is defined for " & _
                            vbCrLf & "parameter {0} of method {1}.", _
                            paramInfo.Name, mInfo.Name)
                    End If
                    
                    ' See if ParamUsageAttribute is defined.  
                    ' If so, display a message.
                    Dim usageAttr As ArgumentUsageAttribute = _
                        Attribute.GetCustomAttribute(paramInfo, _
                            GetType(ArgumentUsageAttribute))

                    If Not (usageAttr Is Nothing) Then
                        Console.WriteLine( vbCrLf & "The " & _
                            "ArgumentUsage attribute is defined for " & _
                            vbCrLf & "parameter {0} of method {1}.", _
                            paramInfo.Name, mInfo.Name)
                        Console.WriteLine( vbCrLf & _
                            "    The usage message for {0} is: " & _
                            vbCrLf & "    ""{1}"".", _
                            paramInfo.Name, usageAttr.Message)
                    End If
                Next paramInfo
            Else
                Console.WriteLine( _
                    "The parameters information could " & _
                    "not be retrieved for method {0}.", mInfo.Name)
            End If
        End Sub

    End Module ' DemoClass
End Namespace ' NDP_UE_VB

' This example of Attribute.GetCustomAttribute( ParameterInfo, Type )
' generates the following output.
' 
' The ArgumentUsage attribute is defined for
' parameter strArray of method TestMethod.
' 
'     The usage message for strArray is:
'     "Must pass an array here.".
' 
' The ParamArray attribute is defined for
' parameter strList of method TestMethod.
' 
' The ArgumentUsage attribute is defined for
' parameter strList of method TestMethod.
' 
'     The usage message for strList is:
'     "Can pass a parameter list or array here.".

注釈

派生型のメソッド内のパラメーターを表す場合 element 、戻り値には、オーバーライドされた基本メソッド内の同じパラメーターに適用される継承可能なカスタム属性が含まれます。

適用対象

次の方法で共有

Attribute.GetCustomAttribute メソッド

定義

オーバーロード

GetCustomAttribute(ParameterInfo, Type, Boolean)

パラメーター

戻り値

例外

例

注釈

適用対象

GetCustomAttribute(MemberInfo, Type, Boolean)

パラメーター

戻り値

例外

例

注釈

適用対象

GetCustomAttribute(Assembly, Type, Boolean)

パラメーター

戻り値

例外

例

注釈

適用対象

GetCustomAttribute(Module, Type, Boolean)

パラメーター

戻り値

例外

例

適用対象

GetCustomAttribute(Module, Type)

パラメーター

戻り値

例外

例

適用対象

GetCustomAttribute(MemberInfo, Type)

パラメーター

戻り値

例外

例

注釈

適用対象

GetCustomAttribute(Assembly, Type)

パラメーター

戻り値

例外

例

注釈

適用対象

GetCustomAttribute(ParameterInfo, Type)

パラメーター

戻り値

例外

例

注釈

適用対象

その他のリソース