c# - 在类型上找不到事件

Question

我有以下异常

WindowsBase.dll 中出现“System.ArgumentException”类型的未处理异常

附加信息：在类型“ConsoleApplication.ITest”上找不到“事件”事件。

在这个再现中：

using System.Windows; // add reference to WindowsBase

interface IBase
{
    event EventHandler Event;
}

interface ITest : IBase { }

class Test : ITest
{
    public event EventHandler Event;
}

class Program
{
    static void Main(string[] args)
    {
        var test = new Test();
        WeakEventManager<IBase, EventArgs>.AddHandler(test, "Event", (s, e) => { }); // works
        WeakEventManager<ITest, EventArgs>.AddHandler(test, "Event", (s, e) => { }); // exception
    }
}

为什么找不到通过接口继承的事件？此方法引发异常。

Answer 1

关于您的示例，我尝试了各种组合。这是唯一的工作代码。似乎您需要知道事件在继承层次结构中的具体定义位置。

using System.Reflection;
using MS.Internal.WindowsBase;

namespace EventTest
{
    class Program
    {
        static void Main(string[] args)
        {
            var test = new Test();
            WeakEventManager<IBase, EventArgs>.AddHandler(test, "IBaseEvent", (s, e) => { }); // works
            WeakEventManager<ITest, EventArgs>.AddHandler(test, "ITestEvent", (s, e) => { }); // works 
            WeakEventManager<Test, EventArgs>.AddHandler(test, "TestEvent", (s, e) => { }); // works
        }
    }
    interface IBase
    {
        event EventHandler IBaseEvent;
    }

    interface ITest : IBase { event EventHandler ITestEvent; }

    class Test : ITest
    {        
        public event EventHandler IBaseEvent;
        public event EventHandler ITestEvent;
        public event EventHandler TestEvent;
    }
}

到目前为止的整体组合；

            WeakEventManager<IBase, EventArgs>.AddHandler(test, "IBaseEvent", (s, e) => { }); // works
            WeakEventManager<IBase, EventArgs>.AddHandler(test, "ITestEvent", (s, e) => { }); // exception 
            WeakEventManager<IBase, EventArgs>.AddHandler(test, "TestEvent", (s, e) => { }); // exception

            WeakEventManager<ITest, EventArgs>.AddHandler(test, "IBaseEvent", (s, e) => { }); // exception
            WeakEventManager<ITest, EventArgs>.AddHandler(test, "ITestEvent", (s, e) => { }); // works 
            WeakEventManager<ITest, EventArgs>.AddHandler(test, "TestEvent", (s, e) => { }); // exception

            WeakEventManager<Test, EventArgs>.AddHandler(test, "IBaseEvent", (s, e) => { }); // exception
            WeakEventManager<Test, EventArgs>.AddHandler(test, "ITestEvent", (s, e) => { }); // exception 
            WeakEventManager<Test, EventArgs>.AddHandler(test, "TestEvent", (s, e) => { }); // works