vb.net – 在一个处理程序中处理所有事件？

在VB.NET中是否可以轻松编写一个事件处理程序来处理每个触发的事件？我想知道是否可以使用这样的东西制作日志记录系统.

我想做一些像(在伪代码中)的东西：

Public Sub eventHandledEvent(ByVal sender As Object,ByVal e As EventArgs)
    File.Write(sender.EventName)
End Sub

我意识到它会很慢,但它不适用于生产系统,只能作为开发工具.

解决方法

你可以用 reflection做到这一点.这是怎么做的.使用名为TextBox1的文本框创建表单.粘贴以下代码.运行项目并查看即时窗口.

Public Class Form1

  Private Sub Form1_Activated(ByVal sender As Object,ByVal e As System.EventArgs) Handles Me.Activated
    RegisterallEvents(TextBox1,"MyEventHandler")
  End Sub

  Sub MyEventHandler(ByVal sender As Object,ByVal e As EventArgs)
    Debug.WriteLine("An event has fired: sender= " & sender.ToString & ",e=" & e.ToString)
  End Sub
  Sub RegisterallEvents(ByVal obj As Object,ByVal methodName As String)
    'List all events through reflection'
    For Each ei As System.Reflection.EventInfo In obj.GetType().GetEvents()
      Dim handlerType As Type = ei.EventHandlerType
      Dim method As System.Reflection.MethodInfo = Me.GetType().getmethod(methodName)
      'Create a delegate pointing to the method'
      Dim handler As [Delegate] = [Delegate].CreateDelegate(handlerType,Me,method)
      'Register the event through reflection'
      ei.AddEventHandler(obj,handler)
    Next
  End Sub
End Class

这是来自Francesco Balena的书Programming Microsoft Visual Basic 2005 The Language.the techique适用于任何引发事件的对象,而不仅仅是控件.它使用contravariance.

如果你是buy the book,那么有一个完整的解释和一些代码,它们将允许你识别在通用处理程序中触发了哪个事件,并使用正则表达式来处理事件的子集.我觉得我不能在这里发布这么长的摘录.