CustomAttributeBuilder Třída

Definice

Obor názvů:

System.Reflection.Emit

Sestavení:

System.Reflection.Emit.ILGeneration.dll

Zdroj:

CustomAttributeBuilder.cs

Pomáhá vytvářet vlastní atributy.

public ref class CustomAttributeBuilder

public class CustomAttributeBuilder

type CustomAttributeBuilder = class

Public Class CustomAttributeBuilder

Dědičnost

Object

CustomAttributeBuilder

Příklady

Následující ukázka kódu znázorňuje použití nástroje CustomAttributeBuilder.

using namespace System;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;

// We will apply this custom attribute to our dynamic type.
public ref class ClassCreator: public Attribute
{
private:
   String^ creator;

public:

   property String^ Creator 
   {
      String^ get()
      {
         return creator;
      }

   }
   ClassCreator( String^ name )
   {
      this->creator = name;
   }

};


// We will apply this dynamic attribute to our dynamic method.
public ref class DateLastUpdated: public Attribute
{
private:
   String^ dateUpdated;

public:

   property String^ DateUpdated 
   {
      String^ get()
      {
         return dateUpdated;
      }

   }
   DateLastUpdated( String^ theDate )
   {
      this->dateUpdated = theDate;
   }

};

Type^ BuildTypeWithCustomAttributesOnMethod()
{
   AppDomain^ currentDomain = Thread::GetDomain();
   AssemblyName^ myAsmName = gcnew AssemblyName;
   myAsmName->Name = "MyAssembly";
   AssemblyBuilder^ myAsmBuilder = currentDomain->DefineDynamicAssembly( myAsmName, AssemblyBuilderAccess::Run );
   ModuleBuilder^ myModBuilder = myAsmBuilder->DefineDynamicModule( "MyModule" );
   
   // First, we'll build a type with a custom attribute attached.
   TypeBuilder^ myTypeBuilder = myModBuilder->DefineType( "MyType", TypeAttributes::Public );
   array<Type^>^temp6 = {String::typeid};
   array<Type^>^ctorParams = temp6;
   ConstructorInfo^ classCtorInfo = ClassCreator::typeid->GetConstructor( ctorParams );
   array<Object^>^temp0 = {"Joe Programmer"};
   CustomAttributeBuilder^ myCABuilder = gcnew CustomAttributeBuilder( classCtorInfo,temp0 );
   myTypeBuilder->SetCustomAttribute( myCABuilder );
   
   // Now, let's build a method and add a custom attribute to it.
   array<Type^>^temp1 = gcnew array<Type^>(0);
   MethodBuilder^ myMethodBuilder = myTypeBuilder->DefineMethod( "HelloWorld", MethodAttributes::Public, nullptr, temp1 );
   array<Type^>^temp7 = {String::typeid};
   ctorParams = temp7;
   classCtorInfo = DateLastUpdated::typeid->GetConstructor( ctorParams );
   array<Object^>^temp2 = {DateTime::Now.ToString()};
   CustomAttributeBuilder^ myCABuilder2 = gcnew CustomAttributeBuilder( classCtorInfo,temp2 );
   myMethodBuilder->SetCustomAttribute( myCABuilder2 );
   ILGenerator^ myIL = myMethodBuilder->GetILGenerator();
   myIL->EmitWriteLine( "Hello, world!" );
   myIL->Emit( OpCodes::Ret );
   return myTypeBuilder->CreateType();
}

int main()
{
   Type^ myType = BuildTypeWithCustomAttributesOnMethod();
   Object^ myInstance = Activator::CreateInstance( myType );
   array<Object^>^customAttrs = myType->GetCustomAttributes( true );
   Console::WriteLine( "Custom Attributes for Type 'MyType':" );
   Object^ attrVal = nullptr;
   System::Collections::IEnumerator^ myEnum = customAttrs->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ customAttr = safe_cast<Object^>(myEnum->Current);
      array<Object^>^temp3 = gcnew array<Object^>(0);
      attrVal = ClassCreator::typeid->InvokeMember( "Creator", BindingFlags::GetProperty, nullptr, customAttr, temp3 );
      Console::WriteLine( "-- Attribute: [{0} = \"{1}\"]", customAttr, attrVal );
   }

   Console::WriteLine( "Custom Attributes for Method 'HelloWorld()' in 'MyType':" );
   customAttrs = myType->GetMember( "HelloWorld" )[ 0 ]->GetCustomAttributes( true );
   System::Collections::IEnumerator^ myEnum2 = customAttrs->GetEnumerator();
   while ( myEnum2->MoveNext() )
   {
      Object^ customAttr = safe_cast<Object^>(myEnum2->Current);
      array<Object^>^temp4 = gcnew array<Object^>(0);
      attrVal = DateLastUpdated::typeid->InvokeMember( "DateUpdated", BindingFlags::GetProperty, nullptr, customAttr, temp4 );
      Console::WriteLine( "-- Attribute: [{0} = \"{1}\"]", customAttr, attrVal );
   }

   Console::WriteLine( "---" );
   array<Object^>^temp5 = gcnew array<Object^>(0);
   Console::WriteLine( myType->InvokeMember( "HelloWorld", BindingFlags::InvokeMethod, nullptr, myInstance, temp5 ) );
}

using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;

// We will apply this custom attribute to our dynamic type.
public class ClassCreator: Attribute

{
   private string creator;
   public string Creator
   {
    get
    {
       return creator;
    }
   }	

   public ClassCreator(string name)
   {
      this.creator = name;
   }
}

// We will apply this dynamic attribute to our dynamic method.
public class DateLastUpdated: Attribute

{
   private string dateUpdated;
   public string DateUpdated
   {
    get
    {
       return dateUpdated;
    }
   }

   public DateLastUpdated(string theDate)
   {
    this.dateUpdated = theDate;
   }
}

class MethodBuilderCustomAttributesDemo

{

   public static Type BuildTypeWithCustomAttributesOnMethod()
   {
    
    AppDomain currentDomain = Thread.GetDomain();
    
    AssemblyName myAsmName = new AssemblyName();
    myAsmName.Name = "MyAssembly";

    AssemblyBuilder myAsmBuilder = currentDomain.DefineDynamicAssembly(
                       myAsmName, AssemblyBuilderAccess.Run);

    ModuleBuilder myModBuilder = myAsmBuilder.DefineDynamicModule("MyModule");

    // First, we'll build a type with a custom attribute attached.

    TypeBuilder myTypeBuilder = myModBuilder.DefineType("MyType",
                        TypeAttributes.Public);
    
    Type[] ctorParams = new Type[] { typeof(string) };
    ConstructorInfo classCtorInfo = typeof(ClassCreator).GetConstructor(ctorParams);

    CustomAttributeBuilder myCABuilder = new CustomAttributeBuilder(
                        classCtorInfo,
                        new object[] { "Joe Programmer" });

    myTypeBuilder.SetCustomAttribute(myCABuilder);

    // Now, let's build a method and add a custom attribute to it.

    MethodBuilder myMethodBuilder = myTypeBuilder.DefineMethod("HelloWorld",
                    MethodAttributes.Public,
                    null,
                    new Type[] { });

    ctorParams = new Type[] { typeof(string) };
    classCtorInfo = typeof(DateLastUpdated).GetConstructor(ctorParams);

    CustomAttributeBuilder myCABuilder2 = new CustomAttributeBuilder(
                        classCtorInfo,
                        new object[] { DateTime.Now.ToString() });

    myMethodBuilder.SetCustomAttribute(myCABuilder2);

    ILGenerator myIL = myMethodBuilder.GetILGenerator();

    myIL.EmitWriteLine("Hello, world!");
    myIL.Emit(OpCodes.Ret);

    return myTypeBuilder.CreateType();
   }

   public static void Main()
   {

    Type myType = BuildTypeWithCustomAttributesOnMethod();

    object myInstance = Activator.CreateInstance(myType);

    object[] customAttrs = myType.GetCustomAttributes(true);

    Console.WriteLine("Custom Attributes for Type 'MyType':");

    object attrVal = null;

    foreach (object customAttr in customAttrs)
    {
       attrVal = typeof(ClassCreator).InvokeMember("Creator",
                      BindingFlags.GetProperty,
                      null, customAttr, new object[] { });
       Console.WriteLine("-- Attribute: [{0} = \"{1}\"]", customAttr, attrVal);
        }

    Console.WriteLine("Custom Attributes for Method 'HelloWorld()' in 'MyType':");

    customAttrs = myType.GetMember("HelloWorld")[0].GetCustomAttributes(true);	

    foreach (object customAttr in customAttrs)
    {
       attrVal = typeof(DateLastUpdated).InvokeMember("DateUpdated",
                      BindingFlags.GetProperty,
                      null, customAttr, new object[] { });
       Console.WriteLine("-- Attribute: [{0} = \"{1}\"]", customAttr, attrVal);
        }

    Console.WriteLine("---");

    Console.WriteLine(myType.InvokeMember("HelloWorld",
              BindingFlags.InvokeMethod,
              null, myInstance, new object[] { }));
   }
}

Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit

 _


' We will apply this custom attribute to our dynamic type.
Public Class ClassCreator

   Inherits Attribute
   
   Private creator As String
   
   Public ReadOnly Property GetCreator() As String
      Get
         Return creator
      End Get
   End Property
   
   
   Public Sub New(name As String)
      Me.creator = name
   End Sub

End Class
 _ 

' We will apply this dynamic attribute to our dynamic method.
Public Class DateLastUpdated

   Inherits Attribute
   
   Private dateUpdated As String
   
   Public ReadOnly Property GetDateUpdated() As String
      Get
         Return dateUpdated
      End Get
   End Property
   
   
   Public Sub New(theDate As String)
      Me.dateUpdated = theDate
   End Sub

End Class
 _ 

Class MethodBuilderCustomAttributesDemo
   
   Public Shared Function BuildTypeWithCustomAttributesOnMethod() As Type
      
      Dim currentDomain As AppDomain = Thread.GetDomain()
      
      Dim myAsmName As New AssemblyName()
      myAsmName.Name = "MyAssembly"
      
      Dim myAsmBuilder As AssemblyBuilder = currentDomain.DefineDynamicAssembly(myAsmName, _
                            AssemblyBuilderAccess.Run)
      
      Dim myModBuilder As ModuleBuilder = myAsmBuilder.DefineDynamicModule("MyModule")
      
      ' First, we'll build a type with a custom attribute attached.
      Dim myTypeBuilder As TypeBuilder = myModBuilder.DefineType("MyType", _
                            TypeAttributes.Public)
      
      Dim ctorParams() As Type = {GetType(String)}
      Dim classCtorInfo As ConstructorInfo = GetType(ClassCreator).GetConstructor(ctorParams)
      
      Dim myCABuilder As New CustomAttributeBuilder(classCtorInfo, _
                        New Object() {"Joe Programmer"})
      
      myTypeBuilder.SetCustomAttribute(myCABuilder)
      
      ' Now, let's build a method and add a custom attribute to it.
      Dim myMethodBuilder As MethodBuilder = myTypeBuilder.DefineMethod("HelloWorld", _
                    MethodAttributes.Public, Nothing, New Type() {})
      
      ctorParams = New Type() {GetType(String)}
      classCtorInfo = GetType(DateLastUpdated).GetConstructor(ctorParams)
      
      Dim myCABuilder2 As New CustomAttributeBuilder(classCtorInfo, _
                        New Object() {DateTime.Now.ToString()})
      
      myMethodBuilder.SetCustomAttribute(myCABuilder2)
      
      Dim myIL As ILGenerator = myMethodBuilder.GetILGenerator()
      
      myIL.EmitWriteLine("Hello, world!")
      myIL.Emit(OpCodes.Ret)
      
      Return myTypeBuilder.CreateType()

   End Function 'BuildTypeWithCustomAttributesOnMethod
    
   
   Public Shared Sub Main()
      
      Dim myType As Type = BuildTypeWithCustomAttributesOnMethod()
      
      Dim myInstance As Object = Activator.CreateInstance(myType)
      
      Dim customAttrs As Object() = myType.GetCustomAttributes(True)
      
      Console.WriteLine("Custom Attributes for Type 'MyType':")
      
      Dim attrVal As Object = Nothing
      
      Dim customAttr As Object
      For Each customAttr In  customAttrs
         attrVal = GetType(ClassCreator).InvokeMember("GetCreator", _
                        BindingFlags.GetProperty, _
                        Nothing, customAttr, New Object() {})
         Console.WriteLine("-- Attribute: [{0} = ""{1}""]", customAttr, attrVal)
      Next customAttr
      
      Console.WriteLine("Custom Attributes for Method 'HelloWorld()' in 'MyType':")
      
      customAttrs = myType.GetMember("HelloWorld")(0).GetCustomAttributes(True)
      
      For Each customAttr In  customAttrs
         attrVal = GetType(DateLastUpdated).InvokeMember("GetDateUpdated", _
                        BindingFlags.GetProperty, _
                        Nothing, customAttr, New Object() {})
         Console.WriteLine("-- Attribute: [{0} = ""{1}""]", customAttr, attrVal)
      Next customAttr
      
      Console.WriteLine("---")
      
      Console.WriteLine(myType.InvokeMember("HelloWorld", BindingFlags.InvokeMethod, _
                        Nothing, myInstance, New Object() {}))
   End Sub

End Class

Poznámky

K popisu vlastního atributu CustomAttributeBuilder použijte objekt vrácený konstruktorem. Přidružte CustomAttribute objekt k instanci tvůrce voláním SetCustomAttribute metody v této instanci tvůrce. Například vytvořte CustomAttributeBuilder k popisu instance parametru AssemblyCultureAttribute zadáním konstruktoru a jeho argumentu AssemblyCultureAttribute . Pak zavolejte SetCustomAttribute , AssemblyBuilder aby se přidružení vytvořilo.

Konstruktory

CustomAttributeBuilder(ConstructorInfo, Object[])	Inicializuje instanci CustomAttributeBuilder třídy zadané konstruktor pro vlastní atribut a argumenty konstruktoru.
CustomAttributeBuilder(ConstructorInfo, Object[], FieldInfo[], Object[])	Inicializuje instanci CustomAttributeBuilder třídy zadané konstruktor pro vlastní atribut, argumenty konstruktoru a sadu pojmenovaných dvojic pole/hodnota.
CustomAttributeBuilder(ConstructorInfo, Object[], PropertyInfo[], Object[])	Inicializuje instanci CustomAttributeBuilder třídy zadané konstruktor pro vlastní atribut, argumenty konstruktoru a sadu pojmenovaných párů vlastností nebo hodnot.
CustomAttributeBuilder(ConstructorInfo, Object[], PropertyInfo[], Object[], FieldInfo[], Object[])	Inicializuje instanci CustomAttributeBuilder třídy zadané konstruktor pro vlastní atribut, argumenty konstruktoru, sadu pojmenovaných párů vlastností nebo hodnot a sadu pojmenovaných polí nebo hodnot párů.

Metody

Equals(Object)	Určí, zda se zadaný objekt rovná aktuálnímu objektu. (Zděděno od Object)
GetHashCode()	Slouží jako výchozí hashovací funkce. (Zděděno od Object)
GetType()	Získá aktuální Type instanci. (Zděděno od Object)
MemberwiseClone()	Vytvoří mělkou kopii aktuálního Objectsouboru . (Zděděno od Object)
ToString()	Vrátí řetězec, který představuje aktuální objekt. (Zděděno od Object)