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分享动态添加委托失败
public class EventWrapper : EventDescriptor
{
object controlledObject;
EventDescriptor controlledEvent;
EventInfo eventInfo;
/// <summary>
///
/// </summary>
/// <param name="controlledObject"></param>
/// <param name="eventInfo"></param>
public EventWrapper(object controlledObject, EventInfo eventInfo)
: base(eventInfo.GetTargetEventName(), null)
{
this.controlledObject = controlledObject;
this.eventInfo = eventInfo;
foreach (EventDescriptor pd in TypeDescriptor.GetEvents(controlledObject))
{
if (pd.Name == eventInfo.SourceEvent)
{
this.controlledEvent = pd;
break;
}
}
if (this.controlledEvent == null)
throw new System.InvalidOperationException("sourceEvent is not found in controlled object");
}
#region
/// <summary>
///
/// </summary>
/// <param name="component"></param>
/// <param name="value"></param>
public override void AddEventHandler(object component, Delegate value)
{
var ub = UndoRedoManager.GetUndoBufferFor(controlledObject as System.Windows.UIElement);
ub.AddCommand(new ModifyGraphicsObject(controlledObject as System.Windows.UIElement));
//System.Reflection.EventInfo eInfo = ComponentType.GetEvent(Name);
//eInfo.AddEventHandler(controlledObject, value);
controlledEvent.AddEventHandler(controlledObject, value);//这里添加失败怎么回事？
}
/// <summary>
///
/// </summary>
/// <param name="component"></param>
/// <param name="value"></param>
public override void RemoveEventHandler(object component, Delegate value)
{
var ub = UndoRedoManager.GetUndoBufferFor(controlledObject as System.Windows.UIElement);
ub.AddCommand(new ModifyGraphicsObject(controlledObject as System.Windows.UIElement));
controlledEvent.RemoveEventHandler(controlledObject, value);
}
/// <summary>
///
/// </summary>
public override Type ComponentType
{
get
{
return controlledEvent.ComponentType;
}
}
/// <summary>
///
/// </summary>
public override Type EventType
{
get
{
return controlledEvent.EventType;
}
}
/// <summary>
///
/// </summary>
public override bool IsMulticast
{
get { return controlledEvent.IsMulticast; }
}
#endregion
/// <summary>
///
/// </summary>
/// <param name="controlledObject"></param>
/// <param name="eventInfo"></param>
/// <returns></returns>
public static bool CheckIfApplicable(object controlledObject, EventInfo eventInfo)
{
foreach (EventDescriptor pd in TypeDescriptor.GetEvents(controlledObject))
{
if (pd.Name == eventInfo.SourceEvent)
return true;
}
return false;
}
/// <summary>
///
/// </summary>
public object ControlledObject
{
get { return controlledObject; }
}
/// <summary>
///
/// </summary>
public EventDescriptor ControlledEvent
{
get { return controlledEvent; }
}
/// <summary>
///
/// </summary>
internal EventInfo EventInfo
{
get { return eventInfo; }
}
/// <summary>
///
/// </summary>
public override AttributeCollection Attributes
{
get
{
List<Attribute> attrs = new List<Attribute>();
if (eventInfo.Editor != null && eventInfo.Editor.IsSubclassOf(typeof(System.Drawing.Design.UITypeEditor)))
attrs.Add(new EditorAttribute(eventInfo.Editor, typeof(System.Drawing.Design.UITypeEditor)));
if (string.IsNullOrEmpty(eventInfo.Group) == false)
attrs.Add(new CategoryAttribute(eventInfo.Group));
return new AttributeCollection(attrs.ToArray());
}
}
/// <summary>
///
/// </summary>
public override string DisplayName
{
get
{
return eventInfo.GetTargetEventDisplayName();
}
}
/// <summary>
///
/// </summary>
public override string Description
{
get
{
if (string.IsNullOrEmpty(eventInfo.Description))
return controlledEvent.Description;
else
return eventInfo.Description;
}
}
/// <summary>
///
/// </summary>
public override bool IsBrowsable
{
get
{
return controlledEvent.IsBrowsable;
}
}
/// <summary>
///
/// </summary>
public override string Name
{
get
{
return eventInfo.GetTargetEventName();
}
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public override string ToString()
{
return DisplayName;
}
/// <summary>
///
/// </summary>
/// <returns></returns>
public Delegate GetBinding()
{
Delegate[] d = GetObjectEventList(controlledObject, Name, ComponentType);
if (d != null && d.Length > 0)
return d[0];
return null;
}
private Delegate[] GetObjectEventList(object p_Object, string p_EventName, Type p_EventType)
{
PropertyInfo _PropertyInfo = p_Object.GetType().GetProperty("Events", BindingFlags.Instance | BindingFlags.FlattenHierarchy | BindingFlags.IgnoreCase);
PropertyInfo propertyInfo = p_Object.GetType().GetProperty("Events", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.IgnoreCase);
if (_PropertyInfo != null)
{
object _EventList = _PropertyInfo.GetValue(p_Object, null);
if (_EventList != null && _EventList is EventHandlerList)
{
EventHandlerList _List = (EventHandlerList)_EventList;
FieldInfo _FieldInfo = p_EventType.GetField(p_EventName, BindingFlags.Static | BindingFlags.FlattenHierarchy | BindingFlags.IgnoreCase);
if (_FieldInfo == null) return null;
Delegate _ObjectDelegate = _List[_FieldInfo.GetValue(p_Object)];
if (_ObjectDelegate == null) return null;
return _ObjectDelegate.GetInvocationList();
}
}
return null;
}
}
想动态添加委托，重写的AddEventHandler里添加委托失败，怎么回事？
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生财 2015-02-10
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GetEvent("MouseDown");
WPF里没有这个东西
WPF里叫 mouseleftbuttondown
IE11下面经常卡到爆 2015-02-06
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WPF里UIElement采用的都是路由事件
参考
http://www.cnblogs.com/loveis715/archive/2012/04/10/2441513.html
Liekkas 2015-02-05
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貌似用winform 调用GetObjectEventList返回成功，而wpf 调用GetObjectEventList返回失败
於黾 2015-02-05
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把代码和现象反复贴出来好几遍,是没有意义的
你先确定这个函数里到底执行到哪就出问题了
如果它一开始就出问题了,你还是重写方法吧
Liekkas 2015-02-05
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就是获取PropertyInfo得到的是null
Liekkas 2015-02-05
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private Delegate[] GetObjectEventList(object p_Object, string p_EventName, Type p_EventType)
{
PropertyInfo _PropertyInfo = p_Object.GetType().GetProperty("Events", BindingFlags.Instance | BindingFlags.FlattenHierarchy | BindingFlags.IgnoreCase);//这里_PropertyInfo 是空值
PropertyInfo propertyInfo = p_Object.GetType().GetProperty("Events", BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.IgnoreCase);//用NonPublic也是propertyInfo 也是空值
if (_PropertyInfo != null)
{
object _EventList = _PropertyInfo.GetValue(p_Object, null);
if (_EventList != null && _EventList is EventHandlerList)
{
EventHandlerList _List = (EventHandlerList)_EventList;
FieldInfo _FieldInfo = p_EventType.GetField(p_EventName, BindingFlags.Static | BindingFlags.FlattenHierarchy | BindingFlags.IgnoreCase);
if (_FieldInfo == null) return null;
Delegate _ObjectDelegate = _List[_FieldInfo.GetValue(p_Object)];
if (_ObjectDelegate == null) return null;
return _ObjectDelegate.GetInvocationList();
}
}
return null;
}
於黾 2015-02-05
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其实就是Delegate[] GetObjectEventList这东西出问题了呗,放那么多无关代码都是迷惑人的
断点跟,看它到底在哪一句就变成null了
Liekkas 2015-02-05
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没有报错，就是委托添加不了，发现返回的是null
public override void AddEventHandler(object component, Delegate value)
{
var ub = UndoRedoManager.GetUndoBufferFor(controlledObject as System.Windows.UIElement);
ub.AddCommand(new ModifyGraphicsObject(controlledObject as System.Windows.UIElement));
//System.Reflection.EventInfo eInfo = ComponentType.GetEvent(Name);
//eInfo.AddEventHandler(controlledObject, value);
controlledEvent.AddEventHandler(controlledObject, value);
Delegate d = GetBinding();//这里发现返回的是空值
}
private void confirmBtn_Click(object sender, EventArgs e)
{
EventWrapper events = null;
if (eventList.SelectedIndex >= 0)
events = eventList.Items[eventList.SelectedIndex] as EventWrapper;
Delegate d = new System.Windows.Input.MouseButtonEventHandler(aa);
events.AddEventHandler(null, d);
activeEvents[events] = d;
}
IE11下面经常卡到爆 2015-02-05
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报的什么错，事件委托和签名跟你传入的handler一致吗
Liekkas 2015-02-05
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为什么winform有呢？那WPF怎么获取控件的事件的所有委托？
本拉灯 2015-02-05
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是的，你说得很对，winform控件的父类有
protected EventHandlerList Events { get; }
而wpf没有，不知道wpf有没有类似于上面winform的Events 属性[/quote]
木有的。控件的基类没提供事件集合。
Liekkas 2015-02-05
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Liekkas 2015-02-05
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是的，你说得很对，winform控件的父类有
protected EventHandlerList Events { get; }
而wpf没有，不知道wpf有没有类似于上面winform的Events 属性
本拉灯 2015-02-05
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WPF 里面没有Events 这个你要DEBUG WPF的事件方法是啥，
WPF与WIN下不一样地。
Liekkas 2015-02-05
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System.Windows.Controls.Button btn = new System.Windows.Controls.Button();
Delegate d2 = new System.Windows.Input.MouseButtonEventHandler(btn_MouseDown);
System.Reflection.EventInfo eInfo = btn.GetType().GetEvent("MouseDown");
eInfo.AddEventHandler(btn, d2);
PropertyInfo pi = btn.GetType().GetProperty("Events", BindingFlags.Instance | BindingFlags.NonPublic);
EventHandlerList ehl = (EventHandlerList)pi.GetValue(btn, null);
FieldInfo fieldInfo = (typeof(System.Windows.Forms.Control)).GetField("EventMouseDown", BindingFlags.Static | BindingFlags.NonPublic);
Delegate d1 = ehl[fieldInfo.GetValue(null)];
foreach (Delegate del in d1.GetInvocationList())
Console.WriteLine(del.Method.Name);
