vb 纵一苇之所如

  Public Sub DeownloadFile(ByVal networkfile As String, ByVal locationFileName As String, ByVal PaperDownloadLog As String, ByVal strReferer As String)
        For index = 1 To 3 '如获取不了重试3次
            Dim task As NewTaskDelegate = AddressOf TrytoDownloadFile
            Dim asyncResult As IAsyncResult = task.BeginInvoke(networkfile, locationFileName, PaperDownloadLog, strReferer, Nothing, Nothing)
            Dim marktime As Integer = 0
            While Not asyncResult.IsCompleted And marktime < 30 '五分钟内未完成就跳过
                marktime += 1
                'MessageBox.Show("还没完成？那我先sleep" & marktime)
                Threading.Thread.Sleep(1000)
            End While
            Dim result As Integer = task.EndInvoke(asyncResult)
            If result > 0 Then Exit For

        Next

        'Dim result As Integer = task.EndInvoke(asyncResult)
        'MessageBox.Show(result.ToString())
    End Sub

    Private Delegate Function NewTaskDelegate(ByVal networkfile, ByVal locationFileName, ByVal PaperDownloadLog, ByVal strReferer) As Integer
    Public Function TrytoDownloadFile(ByVal networkfile As String, ByVal locationFileName As String, ByVal PaperDownloadLog As String, ByVal strReferer As String)
      

  Public Sub DeownloadFile(ByVal networkfile As String, ByVal locationFileName As String, ByVal PaperDownloadLog As String, ByVal strReferer As String)
        For index = 1 To 3 '如获取不了重试3次
            Dim task As NewTaskDelegate = AddressOf TrytoDownloadFile
            Dim asyncResult As IAsyncResult = task.BeginInvoke(networkfile, locationFileName, PaperDownloadLog, strReferer, Nothing, Nothing)
            Dim marktime As Integer = 0
            While Not asyncResult.IsCompleted And marktime < 30 '五分钟内未完成就跳过
                marktime += 1
                'MessageBox.Show("还没完成？那我先sleep" & marktime)
                Threading.Thread.Sleep(1000)
            End While
            Dim result As Integer = task.EndInvoke(asyncResult)
            If result > 0 Then Exit For


        Next

        'Dim result As Integer = task.EndInvoke(asyncResult)
        'MessageBox.Show(result.ToString())
    End Sub


    Private Delegate Function NewTaskDelegate(ByVal networkfile, ByVal locationFileName, ByVal PaperDownloadLog, ByVal strReferer) As Integer
    Public Function TrytoDownloadFile(ByVal networkfile As String, ByVal locationFileName As String, ByVal PaperDownloadLog As String, ByVal strReferer As String)