动态COM对象在C#中请求未知接口{B86A98CC-DCC0-3205-8777-7911A07DAAAF}
通过QueryInterface()变量在C#中访问的已检测的IDispatch-based COM对象的dynamic日志显示(除其他外)未知的IID {B86A98CC-DCC0-3205-8777-7911A07DAAAF}。谷歌，GitHub和microsoft.com出现了zilch。有人知道这个接口是什么吗?如果是的话，你会用它做什么？
FWIW，对象实例化如下：
var type = Type.GetTypeFromProgID(THE_PROGID);
var obj = (dynamic)Activator.CreateInstance(type);然后立即转储接口查询日志。在LINQPad中我得到了这样的信息：
099AC468 {00000000-0000-0000-C000-000000000046} IUnknown
-------- {C3FCC19E-A970-11D2-8B5A-00A0C9B7C9C4} IManagedObject
099AC420 {B196B283-BAB4-101A-B69C-00AA00341D07} IProvideClassInfo
-------- {AF86E2E0-B12D-4C6A-9C5A-D7AA65101E90} IInspectable
-------- {ECC8691B-C1DB-4DC0-855E-65F6C551AF49} INoMarshal
-------- {94EA2B94-E9CC-49E0-C0FF-EE64CA8F5B90} IAgileObject
-------- {00000003-0000-0000-C000-000000000046} IMarshal
-------- {00000144-0000-0000-C000-000000000046} IRpcOptions
099AC42C {00020400-0000-0000-C000-000000000046} IDispatch
-------- {A6EF9860-C720-11D0-9337-00A0C90DCAA9} IDispatchEx
099AC42C {00020400-0000-0000-C000-000000000046} IDispatch
099AC42C {00020400-0000-0000-C000-000000000046} IDispatch
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
-------- {00000038-0000-0000-C000-000000000046} IWeakReferenceSource
099AC42C {00020400-0000-0000-C000-000000000046} IDispatchC#单元测试用例(VS2015，Framework4.5.2)中的相同代码给出了类似的结果：
0A41BFF0 {00000000-0000-0000-C000-000000000046} IUnknown
-------- {C3FCC19E-A970-11D2-8B5A-00A0C9B7C9C4} IManagedObject
0A41BFA8 {B196B283-BAB4-101A-B69C-00AA00341D07} IProvideClassInfo
-------- {AF86E2E0-B12D-4C6A-9C5A-D7AA65101E90} IInspectable
-------- {ECC8691B-C1DB-4DC0-855E-65F6C551AF49} INoMarshal
-------- {94EA2B94-E9CC-49E0-C0FF-EE64CA8F5B90} IAgileObject
-------- {00000003-0000-0000-C000-000000000046} IMarshal
-------- {00000144-0000-0000-C000-000000000046} IRpcOptions
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
0A41BFB4 {00020400-0000-0000-C000-000000000046} IDispatch
-------- {A6EF9860-C720-11D0-9337-00A0C90DCAA9} IDispatchEx
0A41BFB4 {00020400-0000-0000-C000-000000000046} IDispatch32位模式和64位模式之间没有明显的差别(当然，除了显示指针的宽度之外)。
该对象本身来自德尔福的TAutoObject，这说明了它如何响应IProvideClassInfo查询。但是，对于其他不支持该接口的对象，初始接口查询序列基本上是相同的，不管它们是响应于IDispatch::GetTypeInfoCount()还是响应于1。
但是，每次成员访问不仅导致了对IDispatch的查询，而且还导致了对未知接口的两个查询：
099A5068 {00020400-0000-0000-C000-000000000046} IDispatch
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
099A5068 {00020400-0000-0000-C000-000000000046} IDispatch
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
-------- {B86A98CC-DCC0-3205-8777-7911A07DAAAF}
... and so on ad infinitum ...这是从像这样重复的长串行中剪短的；不可能知道在相应的IDispatch调用之前是未知的查询、括号还是后面的查询。
回应Charlieface的评论:成员可以在如下长串printf语句中访问：
Console.WriteLine("ApartmentType {0}", obj.ApartmentType);如果在将每个成员访问的结果转换为其真正的数据类型后，对未知接口的双重查询就会完全消失，然后再传递给Console.WriteLine()。
Console.WriteLine("ApartmentType {0}", (string)obj.ApartmentType);但是，未知查询似乎是CLR问题，而不是LINQPad问题，因为它也出现在VS2015中。
有谁知道，{B86A98CC-DCC0-3205-8777-7911A07DAAAF}代表的是哪个接口，以及使用它的目的是什么？
回答 1
Stack Overflow用户
发布于 2021-03-07 09:42:51
这是因为您使用的是dynamic关键字，它将触发来自.NET的所有类型的调用。
/// <summary>
/// Creates a meta-object for the specified object.
/// </summary>
/// <param name="value">The object to get a meta-object for.</param>
/// <param name="expression">The expression representing this <see cref="DynamicMetaObject"/> during the dynamic binding process.</param>
/// <returns>
/// If the given object implements <see cref="IDynamicMetaObjectProvider"/> and is not a remote object from outside the current AppDomain,
/// returns the object's specific meta-object returned by <see cref="IDynamicMetaObjectProvider.GetMetaObject"/>. Otherwise a plain new meta-object
/// with no restrictions is created and returned.
/// </returns>
public static DynamicMetaObject Create(object value, Expression expression) {
ContractUtils.RequiresNotNull(expression, "expression");
IDynamicMetaObjectProvider ido = value as IDynamicMetaObjectProvider;
if (ido != null && !RemotingServices.IsObjectOutOfAppDomain(value)) {
var idoMetaObject = ido.GetMetaObject(expression);
if (idoMetaObject == null ||
!idoMetaObject.HasValue ||
idoMetaObject.Value == null ||
(object)idoMetaObject.Expression != (object)expression) {
throw Error.InvalidMetaObjectCreated(ido.GetType());
}
return idoMetaObject;
} else {
return new DynamicMetaObject(expression, BindingRestrictions.Empty, value);
}
}{B86A98CC-DCC0-3205-8777-7911A07DAAAF}是IDynamicMetaObjectProvider的(自动生成) IID，即：typeof(IDynamicMetaObjectProvider).GUID。它是一个纯托管接口，因此它在本机代码中没有用处。
要找到这一点，只需查看调用堆栈，但要确保线程隔离类型与对象兼容，否则将得到RPC远程处理“无用”堆栈。
在我的例子中，我必须在STAThread方法上添加.NET属性：
https://stackoverflow.com/questions/66510188
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