VB.NET AppDomain.DefineDynamicAssembly方法代码示例

' 导入命名空间
Imports System.Reflection
Imports System.Reflection.Emit

Module Test
   
   Sub Main()
      Dim currentDomain As AppDomain = AppDomain.CurrentDomain
      
      InstantiateMyDynamicType(currentDomain)   'Failed!
      
      AddHandler currentDomain.AssemblyResolve, AddressOf MyResolveEventHandler
      
      InstantiateMyDynamicType(currentDomain)   'OK!
   End Sub
   
   Sub InstantiateMyDynamicType(domain As AppDomain)
      Try
         ' You must supply a valid fully qualified assembly name here.
         domain.CreateInstance("Assembly text name, Version, Culture, PublicKeyToken", "MyDynamicType")
      Catch e As Exception
         Console.WriteLine(e.Message)
      End Try
   End Sub
   
   Function MyResolveEventHandler(sender As Object, args As ResolveEventArgs) As System.Reflection.Assembly
      Return DefineDynamicAssembly(DirectCast(sender, AppDomain))
   End Function 'MyResolveEventHandler
   
   Function DefineDynamicAssembly(domain As AppDomain) As System.Reflection.Assembly
      ' Build a dynamic assembly using Reflection Emit API.

      Dim assemblyName As New AssemblyName()
      assemblyName.Name = "MyDynamicAssembly"
      
      Dim assemblyBuilder As AssemblyBuilder = domain.DefineDynamicAssembly(assemblyName, AssemblyBuilderAccess.Run)
      Dim moduleBuilder As ModuleBuilder = assemblyBuilder.DefineDynamicModule("MyDynamicModule")
      Dim typeBuilder As TypeBuilder = moduleBuilder.DefineType("MyDynamicType", TypeAttributes.Public)
      Dim constructorBuilder As ConstructorBuilder = typeBuilder.DefineConstructor(MethodAttributes.Public, CallingConventions.Standard, Nothing)
      Dim ilGenerator As ILGenerator = constructorBuilder.GetILGenerator()
      
      ilGenerator.EmitWriteLine("MyDynamicType instantiated!")
      ilGenerator.Emit(OpCodes.Ret)
      
      typeBuilder.CreateType()
      
      Return assemblyBuilder
   End Function 'DefineDynamicAssembly

End Module 'Test

' 导入命名空间
Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Security

Module Example

    Sub Main()
    
        ' Create a CustomAttributeBuilder for the assembly attribute. 
        ' 
        ' SecurityTransparentAttribute has a parameterless constructor, 
        ' which is retrieved by passing an array of empty types for the
        ' constructor's parameter types. The CustomAttributeBuilder is 
        ' then created by passing the ConstructorInfo and an empty array
        ' of objects to represent the parameters.
        '
        Dim transparentCtor As ConstructorInfo = _
            GetType(SecurityTransparentAttribute).GetConstructor( _
                Type.EmptyTypes)
        Dim transparent As New CustomAttributeBuilder( _
            transparentCtor, _
            New Object() {} )
      
        ' Create a dynamic assembly Imports the attribute. The attribute is
        ' passed as an array with one element.
        Dim aName As New AssemblyName("EmittedAssembly")
        Dim ab As AssemblyBuilder = _
            AppDomain.CurrentDomain.DefineDynamicAssembly( _
                aName, _
                AssemblyBuilderAccess.Run, _
                New CustomAttributeBuilder() { transparent } )

        Dim mb As ModuleBuilder = ab.DefineDynamicModule( aName.Name )
        Dim tb As TypeBuilder = mb.DefineType( _
            "MyDynamicType", _
            TypeAttributes.Public )
        tb.CreateType()

        Console.WriteLine("{0}" & vbLf & "Assembly attributes:", ab)
        For Each attr As Attribute In ab.GetCustomAttributes(True)
            Console.WriteLine(vbTab & "{0}", attr)
        Next
    End Sub
End Module