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);

我在MSDN论坛上找到了一个解决方案。下面的示例代码将删除button1中的所有Click事件。

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        button1.Click += button1_Click;
        button1.Click += button1_Click2;
        button2.Click += button2_Click;
    }

    private void button1_Click(object sender, EventArgs e)  => MessageBox.Show("Hello");
    private void button1_Click2(object sender, EventArgs e) => MessageBox.Show("World");
    private void button2_Click(object sender, EventArgs e)  => RemoveClickEvent(button1);

    private void RemoveClickEvent(Button b)
    {
        FieldInfo f1 = typeof(Control).GetField("EventClick", 
            BindingFlags.Static | BindingFlags.NonPublic);

        object obj = f1.GetValue(b);
        PropertyInfo pi = b.GetType().GetProperty("Events",  
            BindingFlags.NonPublic | BindingFlags.Instance);

        EventHandlerList list = (EventHandlerList)pi.GetValue(b, null);
        list.RemoveHandler(obj, list[obj]);
    }
}

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;

如果你真的要这么做……这需要深思熟虑和相当长的时间。事件处理程序在控件内的事件委托映射中进行管理。你需要

在控件实例中反射并获取此映射。 迭代每个事件，获取委托 每个委托可以依次是一系列链接的事件处理程序。调用obControl。RemoveHandler(事件处理程序)

简而言之，工作量很大。在理论上是可能的。我从没试过这样的东西。

看看是否可以对订阅-退订阶段有更好的控制/纪律。

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]);
            }
        }

    }
}

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");