UnmanagedMarshal 类

定义

public ref class UnmanagedMarshal sealed

[System.Serializable]
public sealed class UnmanagedMarshal

[System.Serializable]
[System.Obsolete("An alternate API is available: Emit the MarshalAs custom attribute instead. http://go.microsoft.com/fwlink/?linkid=14202")]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class UnmanagedMarshal

[<System.Serializable>]
type UnmanagedMarshal = class

[<System.Serializable>]
[<System.Obsolete("An alternate API is available: Emit the MarshalAs custom attribute instead. http://go.microsoft.com/fwlink/?linkid=14202")>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type UnmanagedMarshal = class

Public NotInheritable Class UnmanagedMarshal

继承

Object

UnmanagedMarshal

属性

SerializableAttribute ObsoleteAttribute ComVisibleAttribute

示例

下面的代码示例演示已过时 UnmanagedMarshal 类型的替换代码。 该示例发出名为 EmitMarshalAs.dll的单模块程序集，其中包含名为 的类型 Sample。 类型具有名为 Test的方法，其中一个参数为 类型 String。 代码示例将 MarshalAsAttribute 与 一起 UnmanagedType.BStr 应用于 参数。

可以使用 Ildasm.exe (IL 反汇编程序) 检查发出的程序集，并观察 参数是否标记为 marshal(bstr)。

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Runtime::InteropServices;

void main()
{
    AppDomain^ myDomain = AppDomain::CurrentDomain;
    AssemblyName^ myAsmName = gcnew AssemblyName("EmitMarshalAs");

    AssemblyBuilder^ myAssembly = 
        myDomain->DefineDynamicAssembly(myAsmName, 
            AssemblyBuilderAccess::RunAndSave);

    ModuleBuilder^ myModule = 
        myAssembly->DefineDynamicModule(myAsmName->Name, 
            myAsmName->Name + ".dll");
 
    TypeBuilder^ myType = 
        myModule->DefineType("Sample", TypeAttributes::Public);

    MethodBuilder^ myMethod = 
        myType->DefineMethod("Test", MethodAttributes::Public,
            nullptr, gcnew array<Type^> { String::typeid });


    // Get a parameter builder for the parameter that needs the 
    // attribute, using the HasFieldMarshal attribute. In this
    // example, the parameter is at position 0 and has the name
    // "arg".
    ParameterBuilder^ pb = 
        myMethod->DefineParameter(0, 
            ParameterAttributes::HasFieldMarshal, "arg");

    // Get the MarshalAsAttribute constructor that takes an
    // argument of type UnmanagedType.
    //
    //Type^ maattrType = MarshalAsAttribute::typeid;
    ConstructorInfo^ ci = 
        (MarshalAsAttribute::typeid)->GetConstructor(
            gcnew array<Type^> { UnmanagedType::typeid });

    // Create a CustomAttributeBuilder representing the attribute,
    // specifying the necessary unmanaged type. In this case, 
    // UnmanagedType.BStr is specified.
    //
    CustomAttributeBuilder^ cabuilder = 
        gcnew CustomAttributeBuilder(
            ci, gcnew array<Object^> { UnmanagedType::BStr });

    // Apply the attribute to the parameter.
    //
    pb->SetCustomAttribute(cabuilder);


    ILGenerator^ il = myMethod->GetILGenerator();
    il->Emit(OpCodes::Ret);

    Type^ finished = myType->CreateType();
    myAssembly->Save(myAsmName->Name + ".dll");
}

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

public class Example
{
    public static void Main()
    {
        AppDomain myDomain = AppDomain.CurrentDomain;
        AssemblyName myAsmName = new AssemblyName("EmitMarshalAs");

        AssemblyBuilder myAssembly =
            myDomain.DefineDynamicAssembly(myAsmName,
                AssemblyBuilderAccess.RunAndSave);

        ModuleBuilder myModule =
            myAssembly.DefineDynamicModule(myAsmName.Name,
               myAsmName.Name + ".dll");

        TypeBuilder myType =
            myModule.DefineType("Sample", TypeAttributes.Public);

        MethodBuilder myMethod =
            myType.DefineMethod("Test", MethodAttributes.Public,
                null, new Type[] { typeof(string) });

        // Get a parameter builder for the parameter that needs the
        // attribute, using the HasFieldMarshal attribute. In this
        // example, the parameter is at position 0 and has the name
        // "arg".
        ParameterBuilder pb =
            myMethod.DefineParameter(0,
               ParameterAttributes.HasFieldMarshal, "arg");

        // Get the MarshalAsAttribute constructor that takes an
        // argument of type UnmanagedType.
        //
        ConstructorInfo ci =
            typeof(MarshalAsAttribute).GetConstructor(
                new Type[] { typeof(UnmanagedType) });

        // Create a CustomAttributeBuilder representing the attribute,
        // specifying the necessary unmanaged type. In this case,
        // UnmanagedType.BStr is specified.
        //
        CustomAttributeBuilder cabuilder =
            new CustomAttributeBuilder(
                ci, new object[] { UnmanagedType.BStr });

        // Apply the attribute to the parameter.
        //
        pb.SetCustomAttribute(cabuilder);

        // Emit a dummy method body.
        ILGenerator il = myMethod.GetILGenerator();
        il.Emit(OpCodes.Ret);

        Type finished = myType.CreateType();
        myAssembly.Save(myAsmName.Name + ".dll");
    }
}

Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Runtime.InteropServices

Public Class Example

    Public Shared Sub Main()

        Dim myDomain As AppDomain = AppDomain.CurrentDomain
        Dim myAsmName As New AssemblyName("EmitMarshalAs")

        Dim myAssembly As AssemblyBuilder = _
            myDomain.DefineDynamicAssembly(myAsmName, _
                AssemblyBuilderAccess.RunAndSave)

        Dim myModule As ModuleBuilder = _
            myAssembly.DefineDynamicModule(myAsmName.Name, _
                myAsmName.Name & ".dll")

        Dim myType As TypeBuilder = _
            myModule.DefineType("Sample", TypeAttributes.Public)
        
        Dim myMethod As MethodBuilder = _
            myType.DefineMethod("Test", MethodAttributes.Public, _
                Nothing, new Type() { GetType(String) })


        ' Get a parameter builder for the parameter that needs the 
        ' attribute, using the HasFieldMarshal attribute. In this
        ' example, the parameter is at position 0 and has the name
        ' "arg".
        Dim pb As ParameterBuilder = _
            myMethod.DefineParameter(0, _
               ParameterAttributes.HasFieldMarshal, "arg")

        ' Get the MarshalAsAttribute constructor that takes an
        ' argument of type UnmanagedType.
        '
        Dim ciParameters() As Type = { GetType(UnmanagedType) }
        Dim ci As ConstructorInfo = _
            GetType(MarshalAsAttribute).GetConstructor(ciParameters)

        ' Create a CustomAttributeBuilder representing the attribute,
        ' specifying the necessary unmanaged type. In this case, 
        ' UnmanagedType.BStr is specified.
        '
        Dim ciArguments() As Object = { UnmanagedType.BStr }
        Dim cabuilder As New CustomAttributeBuilder(ci, ciArguments)

        ' Apply the attribute to the parameter.
        '
        pb.SetCustomAttribute(cabuilder)


        ' Emit a dummy method body.
        Dim il As ILGenerator = myMethod.GetILGenerator()
        il.Emit(OpCodes.Ret)

        myType.CreateType()
        myAssembly.Save(myAsmName.Name & ".dll")

    End Sub

End Class

注解

该代码示例演示此已过时类型的解决方法。

封送处理是打包和解压缩参数的过程，以便可以进行远程过程调用。 在封送处理期间，当托管类型的格式不同于相应非托管类型的格式时，字段可能会进行格式转换。 例如，你可能希望将类型 String 封送为非托管 BSTR。 某些格式转换由运行时自动处理。 若要替代默认行为，必须使用 UnmanagedMarshal 类来定义格式转换。

属性

方法

适用于

另请参阅

• Type
• UnmanagedType
• Guid