要在控件上创建新的事件处理程序,可以这样做

c.Click += new EventHandler(mainFormButton_Click);

或者这个

c.Click += mainFormButton_Click;

要删除事件处理程序,可以这样做

c.Click -= mainFormButton_Click;

但是如何从事件中删除所有事件处理程序呢?


当前回答

好吧,这里有另一个解决方案来删除关联事件(如果你已经有一个方法来处理控件的事件):

EventDescriptor ed = TypeDescriptor.GetEvents(this.button1).Find("MouseDown",true);            
Delegate delegate = Delegate.CreateDelegate(typeof(EventHandler), this, "button1_MouseDownClicked");
if(ed!=null) 
    ed.RemoveEventHandler(this.button1, delegate);

其他回答

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(); }

哇。我找到了这个解决方案,但没有一个像我想要的那样有效。但这个太好了:

EventHandlerList listaEventos;

private void btnDetach_Click(object sender, EventArgs e)
{
    listaEventos = DetachEvents(comboBox1);
}

private void btnAttach_Click(object sender, EventArgs e)
{
    AttachEvents(comboBox1, listaEventos);
}

public EventHandlerList DetachEvents(Component obj)
{
    object objNew = obj.GetType().GetConstructor(new Type[] { }).Invoke(new object[] { });
    PropertyInfo propEvents = obj.GetType().GetProperty("Events", BindingFlags.NonPublic | BindingFlags.Instance);

    EventHandlerList eventHandlerList_obj = (EventHandlerList)propEvents.GetValue(obj, null);
    EventHandlerList eventHandlerList_objNew = (EventHandlerList)propEvents.GetValue(objNew, null);

    eventHandlerList_objNew.AddHandlers(eventHandlerList_obj);
    eventHandlerList_obj.Dispose();

    return eventHandlerList_objNew;
}

public void AttachEvents(Component obj, EventHandlerList eventos)
{
    PropertyInfo propEvents = obj.GetType().GetProperty("Events", BindingFlags.NonPublic | BindingFlags.Instance);

    EventHandlerList eventHandlerList_obj = (EventHandlerList)propEvents.GetValue(obj, null);

    eventHandlerList_obj.AddHandlers(eventos);
}

虽然有点晚了,但我使用了这个对我来说非常有效的链接: https://www.codeproject.com/Articles/103542/Removing-Event-Handlers-using-Reflection

这个代码的美妙之处在于它适用于所有人,WFP, Forms, Xamarin Forms。我用它来做沙玛林。请注意,只有当你不拥有这个事件(例如,一个库代码在你不关心的一些事件上崩溃)时,你才需要这种方式使用Reflection。

下面是我稍微修改过的代码:

    static Dictionary<Type, List<FieldInfo>> dicEventFieldInfos = new Dictionary<Type, List<FieldInfo>>();

    static BindingFlags AllBindings
    {
        get { return BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Static; }
    }

    static void BuildEventFields(Type t, List<FieldInfo> lst)
    {
        foreach (EventInfo ei in t.GetEvents(AllBindings))
        {
            Type dt = ei.DeclaringType;
            FieldInfo fi = dt.GetField(ei.Name, AllBindings);
            if (fi != null)
                lst.Add(fi);
        }
    }
    static List<FieldInfo> GetTypeEventFields(Type t)
    {
        if (dicEventFieldInfos.ContainsKey(t))
            return dicEventFieldInfos[t];

        List<FieldInfo> lst = new List<FieldInfo>();
        BuildEventFields(t, lst);
        dicEventFieldInfos.Add(t, lst);
        return lst;
    }
    static EventHandlerList GetStaticEventHandlerList(Type t, object obj)
    {
        MethodInfo mi = t.GetMethod("get_Events", AllBindings);
        return (EventHandlerList)mi.Invoke(obj, new object[] { });
    }
    public static void RemoveEventHandler(object obj, string EventName = "")
    {
        if (obj == null)
            return;

        Type t = obj.GetType();
        List<FieldInfo> event_fields = GetTypeEventFields(t);
        EventHandlerList static_event_handlers = null;

        foreach (FieldInfo fi in event_fields)
        {
            if (EventName != "" && string.Compare(EventName, fi.Name, true) != 0)
                continue;
            var eventName = fi.Name;
            // After hours and hours of research and trial and error, it turns out that
            // STATIC Events have to be treated differently from INSTANCE Events...
            if (fi.IsStatic)
            {
                // STATIC EVENT
                if (static_event_handlers == null)
                    static_event_handlers = GetStaticEventHandlerList(t, obj);

                object idx = fi.GetValue(obj);
                Delegate eh = static_event_handlers[idx];
                if (eh == null)
                    continue;

                Delegate[] dels = eh.GetInvocationList();
                if (dels == null)
                    continue;

                EventInfo ei = t.GetEvent(eventName, AllBindings);
                foreach (Delegate del in dels)
                    ei.RemoveEventHandler(obj, del);
            }
            else
            {
                // INSTANCE EVENT
                EventInfo ei = t.GetEvent(eventName, AllBindings);
                if (ei != null)
                {
                    object val = fi.GetValue(obj);
                    Delegate mdel = (val as Delegate);
                    if (mdel != null)
                    {
                        foreach (Delegate del in mdel.GetInvocationList())
                        {
                            ei.RemoveEventHandler(obj, del);
                        }
                    }
                }
            }
        }
    }


示例用法:RemoveEventHandler(obj, "Focused");

好吧,这里有另一个解决方案来删除关联事件(如果你已经有一个方法来处理控件的事件):

EventDescriptor ed = TypeDescriptor.GetEvents(this.button1).Find("MouseDown",true);            
Delegate delegate = Delegate.CreateDelegate(typeof(EventHandler), this, "button1_MouseDownClicked");
if(ed!=null) 
    ed.RemoveEventHandler(this.button1, delegate);

删除按钮的所有处理程序: save.RemoveEvents ();

public static class EventExtension
{
    public static void RemoveEvents<T>(this T target) where T : Control
    {
       var propInfo = typeof(T).GetProperty("Events", BindingFlags.NonPublic | BindingFlags.Instance);
        var list = (EventHandlerList)propInfo.GetValue(target, null);
        list.Dispose();
    }
}