C# &引用；未能添加事件处理程序"；从COM处理事件时

我有一个COM服务器和一个调用它的Silverlight（OOTB）应用程序。我最近对COM服务器进行了一些重构，我设法打破了服务器和客户机之间的事件处理，我不知道我是如何打破它的。以下是我现在拥有的：

服务器

namespace ServerNS
{
    [Guid("8FFF7AAE-B162-42C2-9F70-269D285CF622")]
    [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
    [ComVisible(true)]
    interface IServerEvents
    {
        [DispId(1)]
        void MyEvent(MyContainer container);
    }

    [Guid("D2F3738D-DD23-472F-9D36-4136E1196890")]
    [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
    [ComVisible(true)]
    public interface IServer
    {
        ...
    }

    [Guid("77253016-1A2A-43CC-A360-04519A4F50F5")]
    [ClassInterface(ClassInterfaceType.None)]
    [ComSourceInterfaces(typeof(IServerEvents))]
    [ProgId("Server.MyServer")]
    [ComVisible(true)]
    public class Server : IServer
    {
        public event MyEventHandler MyEvent;

        public void Trigger(MyContainer container)
        {
            if (MyEvent != null)
            {
                MyEvent(container);
            }
        }
    }
}

客户端

namespace ClientNS
{
    public class Client
    {
        public void Init()
        {
            dynamic comObj = AutomationFactory.CreateObject("Server.MyServer");
            AutomationEvent evt = AutomationFactory.GetEvent(comObj, "MyEvent");

            evt.EventRaised += (sender, e) =>
            {
                //Do Stuff
            }; //Exception occurs here.
        }
    }
}

错误 当我尝试将事件处理程序添加到AutomationEvent时，会出现此异常。这在我的重构（即添加IServerEvents接口）之前起作用。comObj是一个合法的实例——我可以在它上面调用其他COM方法——所以我不明白为什么它似乎找不到那个事件；或者，如果是错误的“失败”部分，如何找出失败的原因

System.Exception was unhandled by user code
  Message=Failed to add event handler. Possible reasons include: the object does not support this or any events, or something failed while adding the event.
  StackTrace:
       at MS.Internal.Error.MarshalXresultAsException(UInt32 hr, COMExceptionBehavior comExceptionBehavior)
       at MS.Internal.XcpImports.CheckHResult(UInt32 hr)
       at MS.Internal.ComAutomation.ComAutomationNative.ConnectEvent(IntPtr nativePeer, String eventName, RaiseComAutomationEventDelegate raiseComAutomationEventDelegate)
       at MS.Internal.ComAutomation.ComAutomationObject.ConnectEvent(String name)
       at System.Runtime.InteropServices.Automation.AutomationEvent.UpdateConnection()
       at System.Runtime.InteropServices.Automation.AutomationEvent.add_EventRaised(EventHandler`1 value)
       at ClientNS.Client.Init()
       at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
       at System.ComponentModel.BackgroundWorker.OnRun(Object argument)

---

事实证明，问题在于接口没有声明为“public”——因此接口需要如下所示：

public interface IServerEvents
{
    [DispId(1)]
    void MyEvent(MyContainer container);
}

}

在OnDocumentComplete中

IHTMLElement htmlElement = document.getElementById("ele");
DHTMLEventHandler Handler = new DHTMLEventHandler((IHTMLDocument2)webBrowser.Document);
Handler.Handler += new DHTMLEvent(Dummy_OnClick);
htmlElement.onclick = Handler;

添加新方法以处理单击事件

void Dummy_OnClick(IHTMLEventObj e){
// DO Action 
}

void Dummy_OnClick(IHTMLEventObj e){
// DO Action 
}