在类型上找不到事件

Question

我有以下异常

An unhandled exception of type 'System.ArgumentException' occurred in WindowsBase.dll

Additional information: 'Event' event not found on type 'ConsoleApplication.ITest'.

在此重现中：

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inherited via interfaces 事件？ this method.

抛出异常

Answer 1

我已经针对您的示例尝试了各种组合。这是这里唯一的工作代码。看来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;
    }
}

到目前为止的全部组合；

            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

在类型上找不到事件

Event not found on type

c#

events

weakeventmanager