How to remove all event handlers from an event

Question

To create a new event handler on a control you can do this

c.Click += new EventHandler(mainFormButton_Click);

or this

c.Cli         


        

Answer 1

This page helped me a lot. The code I got from here was meant to remove a click event from a button. I need to remove double click events from some panels and click events from some buttons. So I made a control extension, which will remove all event handlers for a certain event.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using System.Reflection;
public static class EventExtension
{
    public static void RemoveEvents(this T target, string eventName) where T:Control
    {
        if (ReferenceEquals(target, null)) throw new NullReferenceException("Argument \"target\" may not be null.");
        FieldInfo fieldInfo = typeof(Control).GetField(eventName, BindingFlags.Static | BindingFlags.NonPublic);
        if (ReferenceEquals(fieldInfo, null)) throw new ArgumentException(
            string.Concat("The control ", typeof(T).Name, " does not have a property with the name \"", eventName, "\""), nameof(eventName));
        object eventInstance = fieldInfo.GetValue(target);
        PropertyInfo propInfo = typeof(T).GetProperty("Events", BindingFlags.NonPublic | BindingFlags.Instance);
        EventHandlerList list = (EventHandlerList)propInfo.GetValue(target, null);
        list.RemoveHandler(eventInstance, list[eventInstance]);
    }
}

Now, the usage of this extenstion. If you need to remove click events from a button,

Button button = new Button();
button.RemoveEvents(nameof(button.EventClick));

If you need to remove doubleclick events from a panel,

Panel panel = new Panel();
panel.RemoveEvents(nameof(panel.EventDoubleClick));

I am not an expert in C#, so if there are any bugs please forgive me and kindly let me know about it.