[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum UnmanagedType

type UnmanagedType = 

[<System.Serializable>]
type UnmanagedType = 

[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type UnmanagedType = 

Public Enum UnmanagedType

以下代码片段演示如何在托管源代码中声明由 COM 组件实现的非托管接口。 属性 System.Runtime.InteropServices.ComImportAttribute 可防止 IMyStorage 接口导出回供 COM 使用。 (COM 客户端应直接使用现有的 COM 组件。) 在此示例中， MarshalAsAttribute 指定多个 UnmanagedType 成员，这些成员表示原始 COM 接口使用的类型。

using namespace System;
using namespace System::Runtime::InteropServices;
// If you do not have a type library for an interface
// you can redeclare it using ComImportAttribute.
// This is how the interface would look in an idl file.
//object,
//uuid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26"),
//dual, helpstring("IMyStorage Interface"),
//pointer_default(unique)
//interface IMyStorage : IDispatch
// [id(1)]
// HRESULT GetItem([in] BSTR bstrName, [out, retval] IDispatch ** ppItem);
// [id(2)]
// HRESULT GetItems([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT)* pItems);
// [id(3)]
// HRESULT GetItemDescriptions([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT) ** ppItems);
// [id(4), propget]
// HRESULT get_IsEmpty([out, retval] BOOL * pfEmpty);
// This is the managed declaration.
[ComImport]
[Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")]
interface class IMyStorage
   [DispId(1)]
   Object^ GetItem( [In,MarshalAs(UnmanagedType::BStr)]String^ bstrName );
   //[return : MarshalAs(UnmanagedType::Interface)]
   [DispId(2)]
   void GetItems( [In,MarshalAs(UnmanagedType::BStr)]String^ bstrLocation, [Out,MarshalAs(UnmanagedType::SafeArray,
   SafeArraySubType=VarEnum::VT_VARIANT)]array<Object^>^Items );
   [DispId(3)]
   void GetItemDescriptions( [In]String^ bstrLocation, [In,Out,MarshalAs(UnmanagedType::SafeArray)]array<Object^>^varDescriptions );
   property bool IsEmpty 
      [DispId(4)]
      [returnvalue:MarshalAs(UnmanagedType::VariantBool)]
      bool get();
using System;
using System.Runtime.InteropServices;
namespace MyModule
    // If you do not have a type library for an interface
    // you can redeclare it using ComImportAttribute.
    // This is how the interface would look in an idl file.
    //object,
    //uuid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26"),
    //dual,	helpstring("IMyStorage Interface"),
    //pointer_default(unique)
    //interface IMyStorage : IDispatch
    //	[id(1)]
    //	HRESULT GetItem([in] BSTR bstrName, [out, retval] IDispatch ** ppItem);
    //	[id(2)]
    //	HRESULT GetItems([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT)* pItems);
    //	[id(3)]
    //	HRESULT GetItemDescriptions([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT) ** ppItems);
    //	[id(4), propget]
    //	HRESULT get_IsEmpty([out, retval] BOOL * pfEmpty);
    // This is the managed declaration.
    [ComImport]
    [Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")]
    public interface IMyStorage
        [DispId(1)]
        [return: MarshalAs(UnmanagedType.Interface)]
        object GetItem([In, MarshalAs(UnmanagedType.BStr)] String bstrName);
        [DispId(2)]
        void GetItems([In, MarshalAs(UnmanagedType.BStr)] String bstrLocation,
            [Out, MarshalAs( UnmanagedType.SafeArray,
                      SafeArraySubType = VarEnum.VT_VARIANT )] out Object[] Items);
        [DispId(3)]
        void GetItemDescriptions([In] String bstrLocation,
            [In, Out, MarshalAs(UnmanagedType.SafeArray)] ref Object[] varDescriptions);
        bool IsEmpty
            [DispId(4)]
            [return: MarshalAs(UnmanagedType.VariantBool)]
Imports System.Runtime.InteropServices
Module MyModule
    ' If you do not have a type library for an interface
    ' you can redeclare it using ComImportAttribute.
    ' This is how the interface would look in an idl file.
    'object,
    'uuid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26"),
    'dual,	helpstring("IMyStorage Interface"),
    'pointer_default(unique)
    'interface IMyStorage : IDispatch
    '	[id(1)]
    '	HRESULT GetItem([in] BSTR bstrName, [out, retval] IDispatch ** ppItem);
    '	[id(2)]
    '	HRESULT GetItems([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT)* pItems);
    '	[id(3)]
    '	HRESULT GetItemDescriptions([in] BSTR bstrLocation, [out] SAFEARRAY(VARIANT) ** ppItems);
    '	[id(4), propget]
    '	HRESULT get_IsEmpty([out, retval] BOOL * pfEmpty);
    ' This is the managed declaration.
    <ComImport(), Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")> _
    Public Interface IMyStorage
        <DispId(1)> _
        Function GetItem(<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByVal bstrName As String) _
           As <MarshalAs(UnmanagedType.Interface)> Object
        <DispId(2)> _
        Function GetItems(<InAttribute(), MarshalAs(UnmanagedType.BStr)> ByVal bstrLocation As String, _
           <OutAttribute(), MarshalAs(UnmanagedType.SafeArray, SafeArraySubType := VarEnum.VT_VARIANT)> _
                                      ByVal Items() As Object)
        <DispId(3)> _
        Function GetItemDescriptions(<InAttribute()> ByVal bstrLocation As String, _
           <InAttribute(), OutAttribute(), _
                      MarshalAs(UnmanagedType.SafeArray)> ByRef varDescriptions() As Object)
        <DispId(4)> _
        ReadOnly Property IsEmpty(<MarshalAs(UnmanagedType.VariantBool)> ByVal bEmpty As Boolean)
    End Interface
End Module
              UnmanagedType将 枚举与 属性一起使用System.Runtime.InteropServices.MarshalAsAttribute，以指定在与非托管代码互操作期间如何封送类型。  可以使用此枚举通过简单值类型封送代码， (I1、I2、I4、I8、R4、R8、U2、U4 和 U8) 、.NET Framework 中不可用的非托管类型以及各种其他类型。

有关详细信息，请参阅与非托管代码交互操作。