RemoveHandler 语句
删除事件和事件处理程序之间的关联。
语法
RemoveHandler event, AddressOf eventhandler
组成部分
术语 | 定义 |
---|---|
event |
正在处理的事件的名称。 |
eventhandler |
当前处理事件的过程的名称。 |
注解
使用 AddHandler
和 RemoveHandler
语句,可以在程序执行过程中随时启动和停止特定事件的事件处理。
注意
对于自定义事件,RemoveHandler
语句调用事件的 RemoveHandler
访问器。 有关自定义事件的详细信息,请参阅事件语句。
示例
Sub TestEvents()
Dim Obj As New Class1
' Associate an event handler with an event.
AddHandler Obj.Ev_Event, AddressOf EventHandler
' Call the method to raise the event.
Obj.CauseSomeEvent()
' Stop handling events.
RemoveHandler Obj.Ev_Event, AddressOf EventHandler
' This event will not be handled.
Obj.CauseSomeEvent()
' Associate an event handler with an event, using a lambda.
' This handler cannot be removed.
AddHandler Obj.Ev_Event, Sub ()
MsgBox("Lambda caught event.")
End Sub
' This event will be handled by the lambda above.
Obj.CauseSomeEvent()
End Sub
Sub EventHandler()
' Handle the event.
MsgBox("EventHandler caught event.")
End Sub
Public Class Class1
' Declare an event.
Public Event Ev_Event()
Sub CauseSomeEvent()
' Raise an event.
RaiseEvent Ev_Event()
End Sub
End Class