AddressOf在Visual Basic .NET中

Question

我有通过代码生成的按钮(动态).我必须将一个事件(相同)与他们联系起来.我用AddHandler button.click, AddressOf mysub.

问题是mysub获取了一个string(mysub(string)),但是AddressOf不接受例程中的参数.我怎样才能做到这一点？使用AddressOf的替代方法.

Public Class Form1

   ...

   Private Sub mysub(ByVal sender As Object, ByVal e As System.EventArgs, ByVal str As String)
      ...
      ...
   End Sub

   ...

   Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

      ...

      While something
         ...
         Dim btn As New Button
         ...
         AddHandler btn.click, AddressOf mysub 'here the issue
      End While

      ...

   End Sub
End Class

Answer 1

听起来你有以下场景

Class MyClass
  Public button As Button

  Public Sub New() 
    AddHandler button.Click AddressOf MySub
  End Sub

  Public Sub MySub(p As String)

  End Sub

End Class

如果是这种情况,那么你有几个选择.最简单的方法是使用辅助方法.让它成为事件处理程序,然后调用该MySub函数

  Public Sub New() 
    AddHandler button.Click AddressOf MyHelper
  End Sub

  Public Sub MyHelper(sender As Object, e As EventArgs)
    MySub(TheStringValue)
  End Sub

编辑

在与OP交谈之后,问题是将Form1_Load函数中的局部传递给MySub方法.如果您使用的是Visual Studio 2010,最简单的方法是使用Sublambda表达式

Dim theString = ...
AddHandler button.Click (Sub (sender, e) MySub(sender, e))

如果您使用早期版本的Visual Studio,则需要手动构建闭包,这有点困难.

Class Closure 
  Public TheForm as Form1
  Public TheString As String
  Public Sub OnClick(sender As Object, e As EventArgs)
    TheForm.MySub(sender, e)
  End Sub
End Class

...

' In Form1_Load
Dim closure As New Closure
closure.TheForm = Me
closure.TehString = get the string 

AddHandler按钮.单击AddressOf closure.OnClick