删除不存在的事件处理程序不会造成任何损害。因此，如果您知道可能存在哪些处理程序，您可以简单地删除它们。我刚遇到过类似的情况。这在某些情况下可能会有帮助。

如:

// Add handlers...
if (something)
{
    c.Click += DoesSomething;
}
else
{
    c.Click += DoesSomethingElse;
}

// Remove handlers...
c.Click -= DoesSomething;
c.Click -= DoesSomethingElse;

我刚刚发现如何在设置WinForms控件的属性时挂起事件。它将删除控件中的所有事件:

namespace CMessWin05
{
    public class EventSuppressor
    {
        Control _source;
        EventHandlerList _sourceEventHandlerList;
        FieldInfo _headFI;
        Dictionary<object, Delegate[]> _handlers;
        PropertyInfo _sourceEventsInfo;
        Type _eventHandlerListType;
        Type _sourceType;


        public EventSuppressor(Control control)
        {
            if (control == null)
                throw new ArgumentNullException("control", "An instance of a control must be provided.");

            _source = control;
            _sourceType = _source.GetType();
            _sourceEventsInfo = _sourceType.GetProperty("Events", BindingFlags.Instance | BindingFlags.NonPublic);
            _sourceEventHandlerList = (EventHandlerList)_sourceEventsInfo.GetValue(_source, null);
            _eventHandlerListType = _sourceEventHandlerList.GetType();
            _headFI = _eventHandlerListType.GetField("head", BindingFlags.Instance | BindingFlags.NonPublic);
        }

        private void BuildList()
        {
            _handlers = new Dictionary<object, Delegate[]>();
            object head = _headFI.GetValue(_sourceEventHandlerList);
            if (head != null)
            {
                Type listEntryType = head.GetType();
                FieldInfo delegateFI = listEntryType.GetField("handler", BindingFlags.Instance | BindingFlags.NonPublic);
                FieldInfo keyFI = listEntryType.GetField("key", BindingFlags.Instance | BindingFlags.NonPublic);
                FieldInfo nextFI = listEntryType.GetField("next", BindingFlags.Instance | BindingFlags.NonPublic);
                BuildListWalk(head, delegateFI, keyFI, nextFI);
            }
        }

        private void BuildListWalk(object entry, FieldInfo delegateFI, FieldInfo keyFI, FieldInfo nextFI)
        {
            if (entry != null)
            {
                Delegate dele = (Delegate)delegateFI.GetValue(entry);
                object key = keyFI.GetValue(entry);
                object next = nextFI.GetValue(entry);

                Delegate[] listeners = dele.GetInvocationList();
                if(listeners != null && listeners.Length > 0)
                    _handlers.Add(key, listeners);

                if (next != null)
                {
                    BuildListWalk(next, delegateFI, keyFI, nextFI);
                }
            }
        }

        public void Resume()
        {
            if (_handlers == null)
                throw new ApplicationException("Events have not been suppressed.");

            foreach (KeyValuePair<object, Delegate[]> pair in _handlers)
            {
                for (int x = 0; x < pair.Value.Length; x++)
                    _sourceEventHandlerList.AddHandler(pair.Key, pair.Value[x]);
            }

            _handlers = null;
        }

        public void Suppress()
        {
            if (_handlers != null)
                throw new ApplicationException("Events are already being suppressed.");

            BuildList();

            foreach (KeyValuePair<object, Delegate[]> pair in _handlers)
            {
                for (int x = pair.Value.Length - 1; x >= 0; x--)
                    _sourceEventHandlerList.RemoveHandler(pair.Key, pair.Value[x]);
            }
        }

    }
}

实际上我在用这个方法，效果很好。我受到了Aeonhack写的代码的“启发”。

    Public Event MyEvent()
    Protected Overrides Sub Dispose(ByVal disposing As Boolean)
        If MyEventEvent IsNot Nothing Then
            For Each d In MyEventEvent.GetInvocationList ' If this throws an exception, try using .ToArray
                RemoveHandler MyEvent, d
            Next
        End If
    End Sub

    ~MyClass()
    {
        if (MyEventEvent != null)
        {
            foreach (var d in MyEventEvent.GetInvocationList())
            {
                MyEventEvent -= (MyEvent)d;
            }
        }

    }

字段MyEventEvent是隐藏的，但它确实存在。

调试过程中，你可以看到d.t target是如何实际处理事件的对象，而d.m ode是如何处理事件的方法。你只需要把它拿掉。

效果很好。不再有对象因为事件处理程序而被GC。

从删除所有事件处理程序:

Directly no, in large part because you cannot simply set the event to null. Indirectly, you could make the actual event private and create a property around it that tracks all of the delegates being added/subtracted to it. Take the following: List<EventHandler> delegates = new List<EventHandler>(); private event EventHandler MyRealEvent; public event EventHandler MyEvent { add { MyRealEvent += value; delegates.Add(value); } remove { MyRealEvent -= value; delegates.Remove(value); } } public void RemoveAllEvents() { foreach(EventHandler eh in delegates) { MyRealEvent -= eh; } delegates.Clear(); }

有时我们不得不使用第三方控件，我们需要构建这些尴尬的解决方案。基于@Anoop Muraleedharan的答案，我创建了这个具有推理类型和ToolStripItem支持的解决方案

    public static void RemoveItemEvents<T>(this T target, string eventName) 
        where T : ToolStripItem
    {            
        RemoveObjectEvents<T>(target, eventName);
    }

    public static void RemoveControlEvents<T>(this T target, string eventName)
        where T : Control
    {
        RemoveObjectEvents<T>(target, eventName);
    }

    private static void RemoveObjectEvents<T>(T target, string Event) where T : class
    {
        var typeOfT = typeof(T);
        var fieldInfo = typeOfT.BaseType.GetField(
            Event, BindingFlags.Static | BindingFlags.NonPublic);
        var provertyValue = fieldInfo.GetValue(target);
        var propertyInfo = typeOfT.GetProperty(
            "Events", BindingFlags.NonPublic | BindingFlags.Instance);
        var eventHandlerList = (EventHandlerList)propertyInfo.GetValue(target, null);
        eventHandlerList.RemoveHandler(provertyValue, eventHandlerList[provertyValue]);
    }

你可以这样使用它

    var toolStripButton = new ToolStripButton();
    toolStripButton.RemoveItemEvents("EventClick");

    var button = new Button();
    button.RemoveControlEvents("EventClick");

你们对自己太苛刻了。很简单:

void OnFormClosing(object sender, FormClosingEventArgs e)
{
    foreach(Delegate d in FindClicked.GetInvocationList())
    {
        FindClicked -= (FindClickedHandler)d;
    }
}