VB Socket.Send 返回“无法立即完成非阻塞套接字操作。”答案

【问题标题】：VB Socket.Send returns "A non blocking socket operation could not be completed immediately."VB Socket.Send 返回“无法立即完成非阻塞套接字操作。”
【发布时间】：2017-01-03 10:24:08
【问题描述】：

我有一台服务器，可以将文件发送给请求它们的客户端。它适用于小于 2 gigs 的文件。但是，当文件超过 2 个演出时，我的服务器会在 Dim 缓冲区 处给我一个溢出错误。我找了一下，发现缓冲区大小可能是（upload.SendBufferSize -1）。但是，改变它会给我一个不同的错误： Upload.Send：无法立即完成非阻塞套接字操作。

我从互联网上搜索了它，一个建议是尝试添加 Upload.Blocking = True 如果发生错误，但随后我收到一个错误，提示 Argument is invalid。

对我的问题有什么建议吗？

Private Sub UploaderAccept(ar As IAsyncResult)
    Dim File As IO.FileInfo = ar.AsyncState
    Dim Upload As Socket = UploadServer.EndAccept(ar)

    '--- Determine size of buffer
    Dim fs As New IO.FileStream(File.FullName, FileMode.Open, FileAccess.Read, FileShare.Read)
    Dim buffer(Upload.SendBufferSize - 1) As Byte
    Dim Sent As Long = 0
    Dim t As Long = 0

    '--- Actual sending
    Do Until Sent >= File.Length
        t = fs.Read(buffer, 0, buffer.Length)
        Upload.Send(buffer, 0, t, SocketFlags.None)

        Sent += t
    Loop

    '--- File transfer done
    fs.Close()

    Upload.BeginDisconnect(False, New AsyncCallback(AddressOf OnDisconnect), upload)
    Upload.Close()
End Sub

【问题讨论】：

标签： file buffer send blocking transfer

【解决方案1】：

好的，我自己搞定了，如果有人需要，你不能通过从异步更改为同步来做到这一点。只需使用：

Upload.BeginSend(buffer, 0, t, SocketFlags.None, New AsyncCallback(AddressOf OnSend), Upload)：

    Do Until Sent >= File.Length
        t = fs.Read(buffer, 0, buffer.Length)
        If t > 0 Then
            Upload.BeginSend(buffer, 0, t, SocketFlags.None, New AsyncCallback(AddressOf UploadOnSend), Upload)
        End If

        Sent += t
        TextUpdate(lblFilePerc, Sent)
    Loop
    Close streams...

Private Sub UploadOnSend(ar As IAsyncResult)
    Dim upload As Socket = ar.AsyncState
    upload.EndSend(ar)

End Sub

【讨论】：