VB.net AddHandler与索引

Question

我有一个多线程程序，从互联网下载信息从不同的代理。我有它工作正常，但我必须为每个线程添加功能，以便我知道哪个线程正在处理。所以如果我想要10个线程，我需要10个名为processItems0，processItems1，processItems2等的函数。我的processItems0函数所做的就是将数据传递给具有索引的另一个函数。我希望我可以像processItems（0）那样做一些事情，这样我就可以拥有1个函数，并且不需要一堆if语句来跟踪数据来自哪个webclient。我希望它支持100线程，如果我想要它。即将开展的工作，但它不能成为最好的方式。在此先感谢

Dim wc As New WebClient 
''' if statements that i want to get rid of 
If wcn = 0 Then 
    AddHandler wc.UploadStringCompleted, AddressOf processItems0 
ElseIf wcn = 1 Then 
    AddHandler wc.UploadStringCompleted, AddressOf processItems1 
end if 

wc.Proxy = wp(wcn) 

Dim u As New Uri(laurl) 
wc.UploadStringAsync(u, data) 


''' individual functions for each webclient i want to run.. t 
Private Sub processItems0(ByVal sender As Object, ByVal e As UploadStringCompletedEventArgs) 
    If e.Cancelled = False AndAlso e.Error Is Nothing Then 
     processData(CStr(e.Result), 0) 
    End If 
End Sub 


Private Sub processItems1(ByVal sender As Object, ByVal e As UploadStringCompletedEventArgs) 
    If e.Cancelled = False AndAlso e.Error Is Nothing Then 
     processData(CStr(e.Result), 1) 
    End If 
End Sub 

Private Sub processData(data As String, wcn As Integer) 
    'process data 
end Sub 

Answer 1

请记住删除您的事件处理程序，以防止内存泄漏。

Public Class ProxyWrapper 
    Inherits WebClient 

    Private _index As Integer 

    Public Sub New(ByVal index As Integer) 
     _index = index 
    End Sub 

    Public ReadOnly Property Index As Integer 
     Get 
      Return _index 
     End Get 
    End Property 

    Public Sub RegisterEvent() 
     AddHandler Me.UploadStringCompleted, AddressOf processItems 
    End Sub 

    Public Sub UnregisterEvent() 
     RemoveHandler Me.UploadStringCompleted, AddressOf processItems 
    End Sub 

    Private Sub ProcessItems(ByVal sender As Object, ByVal e As UploadStringCompletedEventArgs) 
     If e.Cancelled = False AndAlso e.Error Is Nothing Then 
      ProcessData(CStr(e.Result), _index) 
     End If 
    End Sub 

    Private Sub ProcessData(ByVal res As String, ByVal index As Integer) 
     ' Handle data 
    End Sub 

End Class