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
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");
其他回答
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");
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");
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();
}
}
我讨厌这里展示的任何完整的解决方案，我现在做了一个混合和测试，为任何事件处理程序工作:
public class MyMain()
public void MyMethod() {
AnotherClass.TheEventHandler += DoSomeThing;
}
private void DoSomething(object sender, EventArgs e) {
Debug.WriteLine("I did something");
AnotherClass.ClearAllDelegatesOfTheEventHandler();
}
}
public static class AnotherClass {
public static event EventHandler TheEventHandler;
public static void ClearAllDelegatesOfTheEventHandler() {
foreach (Delegate d in TheEventHandler.GetInvocationList())
{
TheEventHandler -= (EventHandler)d;
}
}
}
简单!感谢Stephen Punak。
我使用它是因为我使用一个通用的本地方法来删除委托，当设置不同的委托时，在不同的情况下调用本地方法。
斯蒂芬是对的。这很简单:
public event EventHandler<Cles_graph_doivent_etre_redessines> les_graph_doivent_etre_redessines;
public void remove_event()
{
if (this.les_graph_doivent_etre_redessines != null)
{
foreach (EventHandler<Cles_graph_doivent_etre_redessines> F_les_graph_doivent_etre_redessines in this.les_graph_doivent_etre_redessines.GetInvocationList())
{
this.les_graph_doivent_etre_redessines -= F_les_graph_doivent_etre_redessines;
}
}
}
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