如何手动调用事件？ [英] How to manually invoke an event?

问题描述

我在C＃中有以下行：

_timer.ElapsedTick += _somefunction1;
_timer.ElapsedTick += _somefunction2;
_timer.ElapsedTick += _somefunction3;

如何调用订阅_timer.ElapsedTick的所有方法，而不指定_some函数？在这个伪线的某处

How to invoke all methods subscribed to _timer.ElapsedTick without specifying the _somefunction ? Somewhere along this pseudo-line

invoke(_timer.ElapsedTick);

您的帮助非常感谢。

更新

来自@ M.Babcock的示例正在工作。 FireEvent方法有魔法。谢谢。

Example from @M.Babcock is working. The FireEvent method does the magic. Thank you.

class InvokeFromMe
{
    public event EventHandler RaiseMe;
}
class MainClass
{
    public MainClass()
    {
        InvokeFromMe fromMe = new InvokeFromMe();
        fromMe.RaiseMe += fromMe_RaiseMe;
        fromMe.RaiseMe += fromMe_RaiseMe1;
        FireEvent(fromMe, "RaiseMe", null, EventArgs.Empty);
        //works

        System.Timers.Timer _timer = new System.Timers.Timer();
        _timer.Elapsed += _timer_Elapsed;
        FireEvent(_timer, "onIntervalElapsed", null, null);
        //throws exception
    }
    private void _timer_Elapsed(object sender, ElapsedEventArgs e)
    {
        Console.WriteLine("_timer_Elapsed raised");
    }
    private void fromMe_RaiseMe(object sender, EventArgs e)
    {
        Console.WriteLine("Event Handler 0 Raised");
    }
    private void fromMe_RaiseMe1(object sender, EventArgs e)
    {
        Console.WriteLine("Event Handler 1 Raised");
    }
    public void FireEvent(object onMe, string invokeMe, params object[] eventParams)
    {
        MulticastDelegate eventDelagate =
              (MulticastDelegate)onMe.GetType().GetField(invokeMe,
               System.Reflection.BindingFlags.Instance |
               System.Reflection.BindingFlags.NonPublic).GetValue(onMe);

        Delegate[] delegates = eventDelagate.GetInvocationList();

        foreach (Delegate dlg in delegates)
        {
            dlg.Method.Invoke(dlg.Target, eventParams);
        }
    }
}
class Program
{
    static void Main(string[] args)
    {
        MainClass m = new MainClass();
    }
}

推荐答案

可以它使用传统的C＃？否（如前所述）。但是使用反射是有可能的。这是基于这个MSDN论坛主题：

Can it be done using conventional C#? No (as previously stated). But using reflection it is possible. Here is some tested code based on the answer to this MSDN forum thread:

class InvokeFromMe
{
    public event EventHandler RaiseMe;
}

class Program
{
    static void Main(string[] args)
    {
        var fromMe = new InvokeFromMe();

        fromMe.RaiseMe += fromMe_RaiseMe;
        fromMe.RaiseMe += fromMe_RaiseMe1;
        fromMe.RaiseMe += fromMe_RaiseMe2;

        FireEvent(fromMe, "RaiseMe", null, EventArgs.Empty);
    }

    static void fromMe_RaiseMe(object sender, EventArgs e)
    {
        Console.WriteLine("Event Handler 0 Raised");
    }
    static void fromMe_RaiseMe1(object sender, EventArgs e)
    {
        Console.WriteLine("Event Handler 1 Raised");
    }
    static void fromMe_RaiseMe2(object sender, EventArgs e)
    {
        Console.WriteLine("Event Handler 2 Raised");
    }

    public static void FireEvent(object onMe, string invokeMe, params object[] eventParams)
    {
        MulticastDelegate eventDelagate =
              (MulticastDelegate)onMe.GetType().GetField(invokeMe,
               System.Reflection.BindingFlags.Instance |
               System.Reflection.BindingFlags.NonPublic).GetValue(onMe);

        Delegate[] delegates = eventDelagate.GetInvocationList();

        foreach (Delegate dlg in delegates)
        {
            dlg.Method.Invoke(dlg.Target, eventParams);
        }
    } 

}

更新

我不熟悉 System.Timer.Timer 类，所以我我不知道与我提供的例子有什么不同。您可以尝试以下方式：

I'm not familiar with the System.Timer.Timer class, so I'm not sure what is different from my provided example. You could perhaps try something like:

public static void FirePublicEvent(object onMe, string invokeMe, params object[] eventParams)
{
    MulticastDelegate eventDelagate =
          (MulticastDelegate)onMe.GetType().GetField(invokeMe,
           System.Reflection.BindingFlags.Instance |
           System.Reflection.BindingFlags.Public).GetValue(onMe);

    Delegate[] delegates = eventDelagate.GetInvocationList();

    foreach (Delegate dlg in delegates)
    {
       dlg.Method.Invoke(dlg.Target, eventParams);
    }
} 

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