4

我坐在我的电脑前想知道如何获得所有添加的事件。我刚刚阅读了一些文章，包括AC# Bedtime Story以更好地理解事件，我认为我现在明白了主要思想。但是我仍然不知道如何获取在触发事件时执行的方法/委托的列表。实际上，就我而言，如果我知道是否将任何方法/委托分配给某个事件就足够了。例如：我正在使用Gma.UserActivityMonitor（用于键盘/鼠标挂钩）现在我想知道事件HookManager.KeyUp事件是否不为空。如果为空，则添加代表喊声。在我的情况下这个\ /

HookManager.KeyUp += new KeyEventHandler(HookManager_KeyUp);

编辑

示例代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Reflection;
using Gma.UserActivityMonitor;

namespace EventTest 
{ 
    public partial class Form1 : Form 
    { 
        public Form1() 
        { 
            InitializeComponent();             
            HookManager.KeyUp += new KeyEventHandler(HookManager_KeyUp);
            Delegate[] a = GetEventSubscribers(button1, "Click");
            label1.Text = a[0].Method.ToString();
        } 
        void HookManager_KeyUp(object sender, KeyEventArgs e) 
        {         
            /* Do something*/     
        } 
        bool NoEventAttached() 
        { 
            return false; 
        }

        public static Delegate[] GetEventSubscribers(object target, string eventName) 
        { 
            Type t = target.GetType(); 
            var eventInfo = t.GetEvent(eventName, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static); 

            do 
            { 
                FieldInfo[] fia = t.GetFields(
                    BindingFlags.Static | 
                    BindingFlags.Instance | 
                    BindingFlags.NonPublic); 

                foreach (FieldInfo fi in fia) 
                { 
                    if (fi.Name == eventName) 
                    { 
                        Delegate d = fi.GetValue(target) as Delegate;                         
                        if (d != null)                         
                            return d.GetInvocationList(); 
                    } 
                    else if (fi.FieldType == typeof(EventHandlerList)) 
                    { 
                        ----> var obj = fi.GetValue(target) as EventHandlerList; 
                        var eventHandlerFieldInfo = obj.GetType().GetField("head", BindingFlags.Instance | BindingFlags.NonPublic); 
                        do 
                        { 
                            var listEntry = eventHandlerFieldInfo.GetValue(obj); 
                            var handler = listEntry.GetType().GetField("handler", BindingFlags.Instance | BindingFlags.NonPublic); 
                            if (handler != null) 
                            { 
                                var subD = handler.GetValue(listEntry) as Delegate; 
                                if (subD.GetType() != eventInfo.EventHandlerType) 
                                { 
                                    eventHandlerFieldInfo = listEntry.GetType().GetField("next", BindingFlags.Instance | BindingFlags.NonPublic); 
                                    obj = listEntry as EventHandlerList; <-----------
                                    continue; 
                                } 
                                if (subD != null) 
                                { 
                                    return subD.GetInvocationList(); 
                                } 
                            } 
                        } 
                        while (eventHandlerFieldInfo != null);                 
                    } 
                } 
                t = t.BaseType; 
            } while (t != null);          
            return new Delegate[] { }; 
        }

        private void button1_Click(object sender, EventArgs e)
        {

        }

        private void button1_MouseClick(object sender, MouseEventArgs e)
        {

        }


    } 
}
4

2 回答 2

5

请注意此控制台应用程序，特别是调用GetInvocationList(). 该方法返回附加的委托列表。每个Delegate人都有一个Method财产。每个Method属性都有一个Name.

代表归您所有

internal class Program
{
    public event EventHandler CheckInvocationList;

    private static void Main(string[] args)
    {
        Program p = new Program();
        p.CheckInvocationList += new EventHandler(p_CheckInvocationList);
        p.Method1();

        Console.WriteLine(string.Join(" | ", p.CheckInvocationList.GetInvocationList().Select(d => d.Method.Name).ToArray()));
    }

    static void p_CheckInvocationList(object sender, EventArgs e)
    {
        throw new NotImplementedException();
    }

    public void Method1()
    {
        this.CheckInvocationList += new EventHandler(Program_CheckInvocationList);
    }

    void Program_CheckInvocationList(object sender, EventArgs e)
    {
        throw new NotImplementedException();
    }
}

代表不归您所有

好的，这有点混乱，但它会给你你想要的答案。即使内部实现使用一个EventHandlerList（这有点常见），但我不能保证它绝对适用于所有场景，因为可能有很多不同的内部表示。

但是，希望这对您有用。正如您在示例中看到的那样，我使用BackgroundWorker该类作为示例类来获取我不拥有的特定事件的调用列表。

using System;
using System.ComponentModel;
using System.Linq;
using System.Reflection;

internal class Program
{
    private static void Main(string[] args)
    {
        BackgroundWorker worker = new BackgroundWorker();
        worker.DoWork += new DoWorkEventHandler(worker_DoWork);
        worker.DoWork += new DoWorkEventHandler(worker_DoWork2);
        worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(worker_RunWorkerCompleted);
        worker.ProgressChanged += new ProgressChangedEventHandler(worker_ProgressChanged);

        Console.WriteLine(string.Join(" | ", GetEventSubscribers(worker, "DoWork").Select(d => d.Method.Name).ToArray()));
    }

    static void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        throw new NotImplementedException();
    }

    static void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        throw new NotImplementedException();
    }

    static void worker_DoWork2(object sender, DoWorkEventArgs e)
    {
        throw new NotImplementedException();
    }

    static void worker_DoWork(object sender, DoWorkEventArgs e)
    {
        throw new System.NotImplementedException();
    }

    public static Delegate[] GetEventSubscribers(object target, string eventName)
    {
        Type t = target.GetType();
        var eventInfo = t.GetEvent(eventName, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Static);

        do
        {
            FieldInfo[] fia = t.GetFields(
                 BindingFlags.Static |
                 BindingFlags.Instance |
                 BindingFlags.NonPublic);

            foreach (FieldInfo fi in fia)
            {
                if (fi.Name == eventName)
                {
                    Delegate d = fi.GetValue(target) as Delegate;
                    if (d != null)
                        return d.GetInvocationList();
                }
                else if (fi.FieldType == typeof(EventHandlerList))
                {
                    dynamic obj = fi.GetValue(target) as EventHandlerList;
                    var eventHandlerFieldInfo = obj.GetType().GetField("head", BindingFlags.Instance | BindingFlags.NonPublic);
                    do
                    {
                        var listEntry = eventHandlerFieldInfo.GetValue(obj);
                        var handler = listEntry.GetType().GetField("handler", BindingFlags.Instance | BindingFlags.NonPublic);
                        if (handler != null)
                        {
                            var subD = handler.GetValue(listEntry) as Delegate;
                            if (subD.GetType() != eventInfo.EventHandlerType)
                            {
                                eventHandlerFieldInfo = listEntry.GetType().GetField("next", BindingFlags.Instance | BindingFlags.NonPublic);
                                obj = listEntry;
                                continue;
                            }
                            if (subD != null)
                            {
                                return subD.GetInvocationList();
                            }
                        }
                    }
                    while (eventHandlerFieldInfo != null);
                }
            }

            t = t.BaseType;
        } while (t != null);

        return new Delegate[] { };
    }
}

最后，虽然我对代码做了一些相当大的修改，但我必须感谢Bob Powell让我开始着手这件事。

于 2012-09-18T11:55:12.357 回答
1

我相信只需将 HookManager.KeyUp 与 null 进行比较即可为您提供答案。

不过，除此之外，除非自从上次我调查它（很有可能）以来事情发生了变化，否则很难获得与事件相关联的代表的实际列表。但是，如果该值为 null，则表明没有委托与之关联。

于 2012-09-18T11:41:47.283 回答