观察控制确定被解雇的事件？ [英] Watch control to determine events being fired?

问题描述

有没有办法列出具体的WinForms控制所有触发的事件，而不对每个可能的事件明确创建处理程序？例如，我可能希望看到，在各种数据绑定操作一个DataGridView和BindingSource的之间的触发事件的顺序。

Is there a way to list all fired events for specific WinForms controls without explicitly creating a handler for each possible event? For example, I might want to see the sequence of events that fire between a DataGridView and the BindingSource during various databinding actions.

推荐答案

你可以使用反射，但它会是因为所涉及的各种事件处理程序的签名有点棘手。基本上，你必须获得 EventInfo 在每个类型的事件，并使用的 EventHandlerType 财产摸出什么委托类型调用的 的addEventHandler 。 Delegate.CreateDelegate 工程虽然遵循正常的事件处理模式...

You could use reflection, but it's going to be slightly tricky because of the various event handler signatures involved. Basically you'd have to get the EventInfo for each event in the type, and use the EventHandlerType property to work out what delegate type to create before calling AddEventHandler. Delegate.CreateDelegate works for everything that follows the normal event handler pattern though...

基尔的一个示例应用程序的一切。请注意，没有做任何检查 - 如果你给它一个非标准事件的东西它会抛出异常。你可以很容易使用反射来打印出事件的args太

Gere's a sample app. Note that it's not doing any checking - if you give it something with a "non-standard" event it will throw an exception. You could fairly easily use reflection to print out the event args too.

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Reflection;

namespace ConsoleApp
{
    class Program
    {
        [STAThread]
        static void Main(string[] args)
        {
            Form form = new Form { Size = new Size(400, 200) };
            Button button = new Button { Text = "Click me" };
            form.Controls.Add(button);
            EventSubscriber.SubscribeAll(button);
            Application.Run(form);
        }
    }

    class EventSubscriber
    {
        private static readonly MethodInfo HandleMethod = 
            typeof(EventSubscriber)
                .GetMethod("HandleEvent", 
                           BindingFlags.Instance | 
                           BindingFlags.NonPublic);

        private readonly EventInfo evt;

        private EventSubscriber(EventInfo evt)
        {
            this.evt = evt;
        }

        private void HandleEvent(object sender, EventArgs args)
        {
            Console.WriteLine("Event {0} fired", evt.Name);
        }

        private void Subscribe(object target)
        {
            Delegate handler = Delegate.CreateDelegate(
                evt.EventHandlerType, this, HandleMethod);
            evt.AddEventHandler(target, handler);
        }

        public static void SubscribeAll(object target)
        {
            foreach (EventInfo evt in target.GetType().GetEvents())
            {
                EventSubscriber subscriber = new EventSubscriber(evt);
                subscriber.Subscribe(target);
            }
        }
    }
}

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