ParameterInfo.GetCustomAttributes 方法

定义

命名空间:

System.Reflection

程序集:

System.Runtime.dll

获取应用于此参数的自定义属性。

重载

GetCustomAttributes(Type, Boolean)	获取应用于此参数的指定类型或其派生类型的自定义属性。
GetCustomAttributes(Boolean)	获取此参数上定义的所有自定义属性。

GetCustomAttributes(Type, Boolean)

Source:

ParameterInfo.cs

获取应用于此参数的指定类型或其派生类型的自定义属性。

public:
 virtual cli::array <System::Object ^> ^ GetCustomAttributes(Type ^ attributeType, bool inherit);

public virtual object[] GetCustomAttributes (Type attributeType, bool inherit);

abstract member GetCustomAttributes : Type * bool -> obj[]
override this.GetCustomAttributes : Type * bool -> obj[]

Public Overridable Function GetCustomAttributes (attributeType As Type, inherit As Boolean) As Object()

参数

attributeType

Type

由类型标识的自定义属性。

inherit

Boolean

对于该类型的对象，将忽略此自变量。

返回

Object[]

一个数组，该数组包含指定类型或其派生类型的自定义属性。

实现

GetCustomAttributes(Type, Boolean)

例外

ArgumentException

该类型必须是由基础运行时系统提供的类型。

ArgumentNullException

attributeType 为 null。

TypeLoadException

无法加载自定义属性类型。

注解

此方法忽略 inherit 参数。 若要在继承链中搜索参数的属性，请使用 方法的适当 Attribute.GetCustomAttributes 重载。

GetCustomAttributes(Boolean)

Source:

ParameterInfo.cs

获取此参数上定义的所有自定义属性。

public:
 virtual cli::array <System::Object ^> ^ GetCustomAttributes(bool inherit);

public virtual object[] GetCustomAttributes (bool inherit);

abstract member GetCustomAttributes : bool -> obj[]
override this.GetCustomAttributes : bool -> obj[]

Public Overridable Function GetCustomAttributes (inherit As Boolean) As Object()

参数

inherit

Boolean

对于该类型的对象，将忽略此自变量。

返回

Object[]

包含应用于此参数的所有自定义属性的数组。

实现

GetCustomAttributes(Boolean)

例外

TypeLoadException

无法加载自定义属性类型。

示例

以下示例演示如何在运行时检索已应用于方法参数的自定义属性。 该示例定义了一个名为 MyAttribute 的自定义属性，该属性可应用于参数。 然后，该示例使用名为 MyClass 的方法定义名为 的 MyMethod类，并应用于 MyAttribute 方法的参数。

运行示例时，它使用 GetCustomAttributes(Boolean) 方法检索已应用于 中 MyClass所有方法的所有参数的自定义属性，并在控制台中显示它们。

using namespace System;
using namespace System::Reflection;

// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets::Parameter)]
public ref class MyAttribute: public Attribute
{
private:
   String^ myName;

public:
   MyAttribute( String^ name )
   {
      myName = name;
   }

   property String^ Name 
   {
      String^ get()
      {
         return myName;
      }
   }
};

// Define a class which has a custom attribute associated with one of the 
// parameters of a method. 
public ref class MyClass1
{
public:
   void MyMethod( 
      [MyAttribute("This is an example parameter attribute")]
      int i ) {}
};

void main()
{
   // Get the type of the class 'MyClass1'.
   Type^ myType = MyClass1::typeid;

   // Get the members associated with the class 'MyClass1'.
   array<MethodInfo^>^myMethods = myType->GetMethods();

   // Display the attributes for each of the parameters of each method of the class 'MyClass1'.
   for ( int i = 0; i < myMethods->Length; i++ )
   {
      // Get the parameters for the method.
      array<ParameterInfo^>^myParameters = myMethods[ i ]->GetParameters();

      if ( myParameters->Length > 0 )
      {
         Console::WriteLine( "\nThe parameters for the method \"{0}\" that have custom attributes are:", myMethods[ i ] );
         for ( int j = 0; j < myParameters->Length; j++ )
         {
            // Get the attributes of type 'MyAttribute' for each parameter.
            array<Object^>^myAttributes = myParameters[ j ]->GetCustomAttributes( MyAttribute::typeid, false );

            if ( myAttributes->Length > 0 )
            {
               Console::WriteLine( "Parameter {0}, name = {1}, type = {2} has attributes:",
                  myParameters[ j ]->Position, 
                  myParameters[ j ]->Name, 
                  myParameters[ j ]->ParameterType );
               for ( int k = 0; k < myAttributes->Length; k++ )
               {
                  Console::WriteLine( "\t{0}", myAttributes[ k ] );
               }
            }
         }
      }
   }
}
/* This code example produces the following output:

The parameters for the method Void MyMethod(Int32) that have custom attributes are :
Parameter 0, name = i, type = System.Int32 has attributes:
        MyAttribute

The parameters for the method Boolean Equals(System.Object) that have custom attributes are :
 */

using System;
using System.Reflection;

// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets.Parameter)]
public class MyAttribute : Attribute
{
    private string myName;
    public MyAttribute(string name)
    {
        myName = name;
    }
    public string Name
    {
        get
        {
            return myName;
        }
    }
}

// Define a class which has a custom attribute associated with one of the
// parameters of a method.
public class MyClass1
{
    public void MyMethod(
        [MyAttribute("This is an example parameter attribute")]
        int i)
    {
        return;
    }
}

public class MemberInfo_GetCustomAttributes
{
    public static void Main()
    {
        // Get the type of the class 'MyClass1'.
        Type myType = typeof(MyClass1);
        // Get the members associated with the class 'MyClass1'.
        MethodInfo[] myMethods = myType.GetMethods();

        // Display the attributes for each of the parameters of each method of the class 'MyClass1'.
        for(int i = 0; i < myMethods.Length; i++)
        {
            // Get the parameters for the method.
            ParameterInfo[] myParameters = myMethods[i].GetParameters();

            if (myParameters.Length > 0)
            {
                Console.WriteLine("\nThe parameters for the method {0} that have custom attributes are :", myMethods[i]);
                for(int j = 0; j < myParameters.Length; j++)
                {
                    // Get the attributes of type 'MyAttribute' for each parameter.
                    Object[] myAttributes = myParameters[j].GetCustomAttributes(typeof(MyAttribute), false);

                    if (myAttributes.Length > 0)
                    {
                        Console.WriteLine("Parameter {0}, name = {1}, type = {2} has attributes: ",
                            myParameters[j].Position, myParameters[j].Name, myParameters[j].ParameterType);
                        for(int k = 0; k < myAttributes.Length; k++)
                        {
                            Console.WriteLine("\t{0}", myAttributes[k]);
                        }
                    }
                }
            }
        }
    }
}
/* This code example produces the following output:

The parameters for the method Void MyMethod(Int32) that have custom attributes are :
Parameter 0, name = i, type = System.Int32 has attributes:
        MyAttribute

The parameters for the method Boolean Equals(System.Object) that have custom attributes are :
 */

Imports System.Reflection

' Define a custom attribute with one named parameter.
<AttributeUsage(AttributeTargets.Parameter)> Public Class MyAttribute
    Inherits Attribute
    Private myName As String

    Public Sub New(ByVal name As String)
        myName = name
    End Sub 

    Public ReadOnly Property Name() As String
        Get
            Return myName
        End Get
    End Property
End Class 

' Define a class which has a custom attribute associated with one of 
' the parameters of a method. 
Public Class MyClass1

    Public Sub MyMethod( _
            <MyAttribute("This is an example parameter attribute")> _
            ByVal i As Integer _
        )
        Return
    End Sub 
End Class 


Public Class MemberInfo_GetCustomAttributes

    Public Shared Sub Main()
        ' Get the type of the class 'MyClass1'.
        Dim myType As Type = GetType(MyClass1)
        ' Get the members associated with the class 'MyClass1'.
        Dim myMethods As MethodInfo() = myType.GetMethods()

        ' Display the attributes for each of the parameters of each method of the class 'MyClass1'.
        For i As Integer = 0 To myMethods.Length - 1
            ' Get the parameters for the method.
            Dim myParameters As ParameterInfo() = myMethods(i).GetParameters()

            If myParameters.Length > 0 Then
                Console.WriteLine(vbCrLf & "The parameters for the method {0} that have custom attributes are : ", myMethods(i))
                For j As Integer = 0 To myParameters.Length - 1
                    ' Get the attributes of type 'MyAttribute' for each parameter.
                    Dim myAttributes As Object() = myParameters(j).GetCustomAttributes(GetType(MyAttribute), False)

                    If myAttributes.Length > 0 Then
                        Console.WriteLine("Parameter {0}, name = {1}, type = {2} has attributes: ", _
                            myParameters(j).Position, myParameters(j).Name, myParameters(j).ParameterType)
                        For k As Integer = 0 To myAttributes.Length - 1
                            Console.WriteLine(vbTab & "{0}", myAttributes(k))
                        Next k
                    End If
                Next j
            End If
        Next i
    End Sub 
End Class 

' This code example produces the following output:
'
'The parameters for the method Void MyMethod(Int32) that have custom attributes are :
'Parameter 0, name = i, type = System.Int32 has attributes:
'        MyAttribute
'
'The parameters for the method Boolean Equals(System.Object) that have custom attributes are :

注解

此方法忽略 inherit 参数。 若要在继承链中搜索参数的属性，请使用 方法的适当 Attribute.GetCustomAttributes 重载。