我可以只公开某些 C# 类 COM 吗?

Can I make only certain C# classes COM-exposed?

我有一个 C# 库项目,该项目旨在通过 COM 从非托管 C++ 代码中使用。

只有 2 或 3 个方法将以这种方式被调用,但我收到这样的警告:

warning : Type library exporter warning processing ''. Warning: Type library exporter encountered a generic type instance in a signature. Generic code may not be exported to COM.

这些属性和方法不是为从 C++ 访问而设计的,事实上它们甚至不是 public 方法,因此它们(肯定)无论如何都不会可见。

真的有两个问题:

最好仔细检查一下,我没有用大量不应该存在的东西使我的类型库膨胀...

我可以像这样声明整个程序集对 COM 不可见(实际上,当您使用 Visual Studio C# class 库模板时,它应该将它自己放在 AssemblyInfo.cs 中) :

// Setting ComVisible to false makes the types in this assembly not visible
// to COM components.  If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(false)]

现在,在每个 class 中,我可以决定它是否对 COM 可见,如下所示:

using System;
using System.Runtime.InteropServices;

namespace ClassLibrary1
{
    [ProgId("MyCoolClass")]
    [ComVisible(true)]
    [ClassInterface(ClassInterfaceType.AutoDual)]
    public class MyCoolVisibleClass
    {
        public void SayHello()
        {
            Console.WriteLine("Hello COM world");
        }

        // explicit non COM visible because it's set to true at class level
        [ComVisible(false)]
        public void SayHello2()
        {
            Console.WriteLine("Hello world");
        }
    }

    // implicit non COM visible
    public class MyCoolInvisibleClass
    {
        public void SayHello()
        {
            Console.WriteLine("Hello world");
        }
    }
}

您可以使用项目属性来注册("Register for COM Interop" 复选框),但我个人使用这样的命令行注册自己(对于 64 位注册表世界):

%windir%\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe ClassLibrary1.dll /codebase /tlb

输出如下:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe ClassLibrary1.dll /codebase /tlb
Microsoft .NET Framework Assembly Registration Utility version 4.8.3752.0
for Microsoft .NET Framework version 4.8.3752.0
Copyright (C) Microsoft Corporation.  All rights reserved.

RegAsm : warning RA0000 : Registering an unsigned assembly with /codebase can cause your assembly to interfere with other applications that may be installed on the same computer. The /codebase switch is intended to be used only with signed assemblies. Please give your assembly a strong name and re-register it.
Types registered successfully
Assembly exported to 'D:\KilroyWasHere\ClassLibrary1.tlb', and the type library was registered successfully

我可以使用 OleView from Windows SDK:

检查 .tlb 中的真实内容