为什么为属性类型生成的包装器选择此接口？

Question

当我要求 Visual Studio 为我的 COM 组件生成运行时可调用包装器时，它正在选择一个奇怪的类型来包装某个接口属性。

这是组件 A 的汇总类型库：

// Generated .IDL file (by the OLE/COM Object Viewer)
// 
// typelib filename: prodist.sts.dll

[
  uuid(DD00B52D-D8F9-4D5C-ADBD-4E05A68A48CB),
  version(5.4),
  custom(DE77BA64-517C-11D1-A2DA-0000F8773CE9, 134218331),
  custom(DE77BA63-517C-11D1-A2DA-0000F8773CE9, 1423075247),
  custom(DE77BA65-517C-11D1-A2DA-0000F8773CE9, "Created by MIDL version 8.00.0603 at Wed Feb 04 16:40:46 2015
"),
  custom(0F21F359-AB84-41E8-9A78-36D110E6D2F9, "prodist.sts")

]
library prodist_sts
{
    // TLib :     // TLib : OLE Automation : {00020430-0000-0000-C000-000000000046}
    importlib("stdole2.tlb");
    // TLib :  : {F11596CA-03EE-4756-B502-0327800ED8B4}
    importlib("prodist.logging.dll");

    // Forward declare all types defined in this typelib
    interface ISts;
    interface IStsSession;
    interface IStream;
    interface ISequentialStream;

    [
      uuid(EE263AAA-67D4-48DD-9DF5-69ED8CF0D0C9)
    ]
    coclass Sts {
        [default] interface ISts;
    };

    [
      odl,
      uuid(8D841E5C-F25B-4C12-B03A-70A899B3A32E),
      dual,
      nonextensible,
      oleautomation
    ]
    interface ISts : IDispatch {
        [id(0x000003e9), propget]
        HRESULT Logging([out, retval] IProdistLoggingHierarchy** value);
        [id(0x000003e9), propput]
        HRESULT Logging(IProdistLoggingHierarchy* value);
        [id(0x000003e8)]
        HRESULT CreateSession([out, retval] IStsSession** result);
    };

    // ...
}

这是组件 B 的类型库：

// Generated .IDL file (by the OLE/COM Object Viewer)
// 
// typelib filename: prodist.sts.rsfn.dll

[
  uuid(C8FBF2B0-9218-4B0D-9509-C394D65F0566),
  version(5.4),
  custom(DE77BA64-517C-11D1-A2DA-0000F8773CE9, 134218331),
  custom(DE77BA63-517C-11D1-A2DA-0000F8773CE9, 1423076189),
  custom(DE77BA65-517C-11D1-A2DA-0000F8773CE9, "Created by MIDL version 8.00.0603 at Wed Feb 04 16:56:28 2015
"),
  custom(0F21F359-AB84-41E8-9A78-36D110E6D2F9, "prodist.sts.rsfn")

]
library prodist_sts_rsfn
{
    // TLib :     // TLib : OLE Automation : {00020430-0000-0000-C000-000000000046}
    importlib("stdole2.tlb");
    // TLib :  : {DD00B52D-D8F9-4D5C-ADBD-4E05A68A48CB}
    importlib("prodist.sts.dll");
    // TLib :  : {F11596CA-03EE-4756-B502-0327800ED8B4}
    importlib("prodist.logging.dll");

    // Forward declare all types defined in this typelib
    interface IApiMensageria2;
    interface IApiMensageria;
    interface IApiMensageriaContext;
    interface IStsRsfn;
    interface IStsRsfnContext;
    interface IStsRsfnSession;

    [
      uuid(914E8C54-E0F0-4322-8803-8E9EEEE03A01)
    ]
    coclass StsRsfn {
        [default] interface IStsRsfn;
    };

    [
      odl,
      uuid(13385FC6-2618-4830-A3A9-703398AA5A0B),
      dual,
      nonextensible,
      oleautomation
    ]
    interface IStsRsfn : IDispatch {
        [id(0x000003e9), propget]
        HRESULT Logging([out, retval] IProdistLoggingHierarchy** value);
        [id(0x000003e9), propput]
        HRESULT Logging(IProdistLoggingHierarchy* value);
        [id(0x000003e8), propget]
        HRESULT Sts([out, retval] ISts** value);
        [id(0x000003e8), propput]
        HRESULT Sts(ISts* value);
        [id(0x000003f1)]
        HRESULT CreateContext([out, retval] IStsRsfnContext** result);
        [id(0x000003f2)]
        HRESULT CreateSession([out, retval] IStsRsfnSession** result);
    };

    // ...
}

这是 Visual Studio 为组件 A 生成的运行时可调用包装器：

[ClassInterface(0)]
[Guid("EE263AAA-67D4-48DD-9DF5-69ED8CF0D0C9")]
[TypeLibType(2)]
public class StsClass : ISts, Sts
{
    public StsClass();

    [DispId(1001)]
    public virtual IProdistLoggingHierarchy Logging { get; set; }

    [DispId(1000)]
    public virtual IStsSession CreateSession();
}

[CoClass(typeof(StsClass))]
[Guid("8D841E5C-F25B-4C12-B03A-70A899B3A32E")]
public interface Sts : ISts
{
}

[Guid("8D841E5C-F25B-4C12-B03A-70A899B3A32E")]
[TypeLibType(4288)]
public interface ISts
{
    [DispId(1001)]
    IProdistLoggingHierarchy Logging { get; set; }

    [DispId(1000)]
    IStsSession CreateSession();
}

这是 Visual Studio 为组件 B 生成的运行时可调用包装器：

[ClassInterface(0)]
[Guid("914E8C54-E0F0-4322-8803-8E9EEEE03A01")]
[TypeLibType(2)]
public class StsRsfnClass : IStsRsfn, StsRsfn
{
    public StsRsfnClass();

    [DispId(1001)]
    public virtual IProdistLoggingHierarchy Logging { get; set; }
    [DispId(1000)]
    public virtual Sts Sts { get; set; }

    [DispId(1009)]
    public virtual IStsRsfnContext CreateContext();
    [DispId(1010)]
    public virtual IStsRsfnSession CreateSession();
}

[CoClass(typeof(StsRsfnClass))]
[Guid("13385FC6-2618-4830-A3A9-703398AA5A0B")]
public interface StsRsfn : IStsRsfn
{
}

[Guid("13385FC6-2618-4830-A3A9-703398AA5A0B")]
[TypeLibType(4288)]
public interface IStsRsfn
{
    [DispId(1001)]
    IProdistLoggingHierarchy Logging { get; set; }
    [DispId(1000)]
    Sts Sts { get; set; }

    [DispId(1009)]
    IStsRsfnContext CreateContext();
    [DispId(1010)]
    IStsRsfnSession CreateSession();
}

为什么Visual Studio选择Sts接口而不是ISts接口来包裹IStsRsfn.Sts属性？

Answer 1

因为接口 ISts 是 Sts 组件类的默认接口，没有其他组件类实现它。

在这种情况下，我猜导入器选择了它曾经认为是某些 coclass 的默认接口并且没有其他实现的接口。

为什么为属性类型生成的包装器选择此接口？

Why is the generated wrapper for property type selecting this interface?

.net

com

rcw

为什么为 属性 类型生成的包装器选择此接口？

Why is the generated wrapper for property type selecting this interface?

.net

com

rcw

为什么为属性类型生成的包装器选择此接口？