通过

ComImportAttribute 类

  • 项目

指示该属性化类型是以前在 COM 中定义的。

**命名空间:**System.Runtime.InteropServices
**程序集:**mscorlib（在 mscorlib.dll 中）

语法

声明
<ComVisibleAttribute(True)> _
<AttributeUsageAttribute(AttributeTargets.Class Or AttributeTargets.Interface, Inherited:=False)> _
Public NotInheritable Class ComImportAttribute
    Inherits Attribute
用法
Dim instance As ComImportAttribute

[ComVisibleAttribute(true)] 
[AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Interface, Inherited=false)] 
public sealed class ComImportAttribute : Attribute

[ComVisibleAttribute(true)] 
[AttributeUsageAttribute(AttributeTargets::Class|AttributeTargets::Interface, Inherited=false)] 
public ref class ComImportAttribute sealed : public Attribute

/** @attribute ComVisibleAttribute(true) */ 
/** @attribute AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Interface, Inherited=false) */ 
public final class ComImportAttribute extends Attribute

ComVisibleAttribute(true) 
AttributeUsageAttribute(AttributeTargets.Class|AttributeTargets.Interface, Inherited=false) 
public final class ComImportAttribute extends Attribute

备注

可将此属性应用于类或接口，不过通常 类型库导入程序 (Tlbimp.exe) 会在导入类型库时为您应用此属性。

ComImportAttribute 是伪自定义属性，它指示一个类型已在以前发布的类型库中定义。公共语言运行库在激活、导出、强迫类型等操作时对这些类型区别对待。

提示

所有由托管对象继承的基 COM 类型必须聚合自由线程封送处理程序 (FTM)。不聚合 FTM 的 COM 类型不能由托管对象继承。

示例

下面的示例演示如何将 ComImportAttribute 应用于托管的接口声明。仅当在源代码中手动生成互操作程序集并且要模拟由 Tlbimp.exe 生成的元数据时，才应用这个属性。

Imports System
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)> 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

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 )]
            get;
        }
    }
}

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();
   }
};

import System.*;
import 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.
    /** @attribute ComImport()
     */
    /** @attribute Guid("73EB4AF8-BE9C-4b49-B3A4-24F4FF657B26")
     */
   public interface IMyStorage
   {
        /** @attribute DispId(1)
         */
        Object GetItem(
        /** @attribute In()
            @attribute MarshalAs(UnmanagedType.BStr)
         */String bstrName);
      
      
        /** @attribute DispId(2)
         */
        void GetItems(
        /** @attribute In()
            @attribute MarshalAs(UnmanagedType.BStr)
         */String bstrLocation,
        /** @attribute Out()
            @attribute MarshalAs(UnmanagedType.SafeArray, 
            SafeArraySubType = VarEnum.VT_VARIANT)
         */Object Items[]);
             
        /** @attribute DispId(3)
         */
        void GetItemDescriptions(
            /** @attribute In()
             */String bstrLocation,
            /** @attribute In()
                @attribute Out()
                @attribute MarshalAs(UnmanagedType.SafeArray)
             */Object varDescriptions[]);
               
        /** @attribute DispId(4)
         */
        /** @return MarshalAs(UnmanagedType.VariantBool)
         */
        boolean get_IsEmpty();
    } //IMyStorage

继承层次结构

System.Object
   System.Attribute
    System.Runtime.InteropServices.ComImportAttribute

线程安全

此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

.NET Compact Framework

受以下版本支持：2.0

请参见

参考

ComImportAttribute 成员
System.Runtime.InteropServices 命名空间

其他资源

类型库导入程序 (Tlbimp.exe)