我需要编写一个通用函数，用于删除Sub和Func的所有事件处理程序（我需要通用函数才能与子例程和函数一起正常工作）。
...问题是我不知道该怎么做，我看到了声明代表的例子，但这并不像我精确的那样通用。
我读过这篇关于 CodeProject 的文章，但代码是 C# 我什么都看不懂：http: //www.codeproject.com/Articles/103542/Removing-Event-Handlers-using-Reflection
这是我唯一能做的：
Public Class Form1
' Call the function to remove all the handlers of "MySub"
' Clear_Handles(Of MySub)
Private Function Clear_Handles(Of T)(ByVal MethodName As T)
' Code to remove all handlers(of "MethodName")
End Function
Private Sub MySub() Handles event1, event2, event3
' bla bla bla
End Sub
End Class
感谢阅读。
更新
我试图将上面的代码转换为VB只是为了尝试但我不能使用它，我不知道如何使用它，这就是我所做的：
Public Class Form1
Private Sub MySub() Handles Button1.Click, Button2.click
' Do nothing
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
' Attempting to remove "Button1.Click" and "Button2.click" events of "MySub()"
PSLib.cEventHelper.RemoveAllEventHandlers(MySub)
End Sub
End Class
...这是翻译后的代码，我不知道它是否有效，因为我不知道如何使用这些方法：
Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.IO
Imports System.Management
Imports System.Reflection
Imports System.Text
Namespace PSLib
'--------------------------------------------------------------------------------
Public NotInheritable Class cEventHelper
Private Sub New()
End Sub
Shared dicEventFieldInfos As New Dictionary(Of Type, List(Of FieldInfo))()
Private Shared ReadOnly Property AllBindings() As BindingFlags
Get
Return BindingFlags.IgnoreCase Or BindingFlags.[Public] Or BindingFlags.NonPublic Or BindingFlags.Instance Or BindingFlags.[Static]
End Get
End Property
'--------------------------------------------------------------------------------
Private Shared Function GetTypeEventFields(t As Type) As List(Of FieldInfo)
If dicEventFieldInfos.ContainsKey(t) Then
Return dicEventFieldInfos(t)
End If
Dim lst As New List(Of FieldInfo)()
BuildEventFields(t, lst)
dicEventFieldInfos.Add(t, lst)
Return lst
End Function
'--------------------------------------------------------------------------------
Private Shared Sub BuildEventFields(t As Type, lst As List(Of FieldInfo))
' Type.GetEvent(s) gets all Events for the type AND it's ancestors
' Type.GetField(s) gets only Fields for the exact type.
' (BindingFlags.FlattenHierarchy only works on PROTECTED & PUBLIC
' doesn't work because Fieds are PRIVATE)
' NEW version of this routine uses .GetEvents and then uses .DeclaringType
' to get the correct ancestor type so that we can get the FieldInfo.
For Each ei As EventInfo In t.GetEvents(AllBindings)
Dim dt As Type = ei.DeclaringType
Dim fi As FieldInfo = dt.GetField(ei.Name, AllBindings)
If fi IsNot Nothing Then
lst.Add(fi)
End If
Next
End Sub
'--------------------------------------------------------------------------------
Private Shared Function GetStaticEventHandlerList(t As Type, obj As Object) As EventHandlerList
Dim mi As MethodInfo = t.GetMethod("get_Events", AllBindings)
Return DirectCast(mi.Invoke(obj, New Object() {}), EventHandlerList)
End Function
'--------------------------------------------------------------------------------
Public Shared Sub RemoveAllEventHandlers(obj As Object)
RemoveEventHandler(obj, "")
End Sub
'--------------------------------------------------------------------------------
Public Shared Sub RemoveEventHandler(obj As Object, EventName As String)
If obj Is Nothing Then
Return
End If
Dim t As Type = obj.[GetType]()
Dim event_fields As List(Of FieldInfo) = GetTypeEventFields(t)
Dim static_event_handlers As EventHandlerList = Nothing
For Each fi As FieldInfo In event_fields
If EventName <> "" AndAlso String.Compare(EventName, fi.Name, True) <> 0 Then
Continue For
End If
' 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 Then
' STATIC EVENT
If static_event_handlers Is Nothing Then
static_event_handlers = GetStaticEventHandlerList(t, obj)
End If
Dim idx As Object = fi.GetValue(obj)
Dim eh As [Delegate] = static_event_handlers(idx)
If eh Is Nothing Then
Continue For
End If
Dim dels As [Delegate]() = eh.GetInvocationList()
If dels Is Nothing Then
Continue For
End If
Dim ei As EventInfo = t.GetEvent(fi.Name, AllBindings)
For Each del As [Delegate] In dels
ei.RemoveEventHandler(obj, del)
Next
Else
' INSTANCE EVENT
Dim ei As EventInfo = t.GetEvent(fi.Name, AllBindings)
If ei IsNot Nothing Then
Dim val As Object = fi.GetValue(obj)
Dim mdel As [Delegate] = TryCast(val, [Delegate])
If mdel IsNot Nothing Then
For Each del As [Delegate] In mdel.GetInvocationList()
ei.RemoveEventHandler(obj, del)
Next
End If
End If
End If
Next
End Sub
End Class
End Namespace
更新
这是我会做的一个例子：
private sub form1_shown() handles me.shown
RemoveAll_EventHandlers(of MyMethod)
' So it will remove: button1.click, button2.click, button3.click
end sub
Private sub MyMethod() handles button1.click, button2.click, button3.click
' Nothing to do here. . .
end sub
public sub RemoveAll_EventHandlers(of T)(byval MethodName as T)
For each evt as event in MethodName : removehandler control.event, addres of(T)
end sub
更新：
你想象的另一个例子......：
Private Sub RemoveAll_EventHandlers(Of T)(ByVal MethodName As T)
For Each ctrl As Control In Me.Controls
For Each evt As EventHandler In Control
RemoveHandler ctrl.evt, addresof(T)
Next
Next
End Sub
private sub form1_shown() handles me.shown
RemoveAll_EventHandlers(of MyMethod)
' So it will remove: button1.click, button2.click, button3.click
end sub
Private sub MyMethod() handles button1.click, button2.click, button3.click
' Nothing to do here. . .
end sub