接收TCP响应 [英] Receiving TCP Response

问题描述

Hi Folks，

我正致力于转换我们使用的工具，该工具使用TCP从VB6到VS2005 +与一台设备进行通信。它曾经使用winsock.ocx，而VS我使用套接字。我已经能够成功地将命令发送到设备，但我无法得到回应。我是TCP通信的新手...

这是旧代码（VB 6）

公共sender1作为新套接字（AddressFamily.InterNetwork，SocketType.Stream，ProtocolType.Tcp）< br> Dim data As String
sender1.GetData data
（Mid $（data，i2 + 1,1）

这是我将它转换为（不成功！）

Dim data As String
frmMain.sender1.Receive（data）
（Mid $（data，i2 + 1,1）

当我收到回复时，我得到一个关于收到null的例外data ...如果我将数据更改为"Dim data as String"""，则会出现System.InvalidCastException

Message ="无法将类型为'System.String'的对象强制转换为类型'System.Collections.Generic.IList`1 [System.ArraySegment`1 [System.Byte]]'。"。

我也尝试将"数据"更改为字节数组，但问题是那就是（Mid $（数据，i2 + 1,1），要求"数据"是一个字符串。

有没有人有任何建议？

解决方案

我会使用字节数组。 Mid

需要字符串参数，所以我会改用Array.CopyTo。

你可以在VB论坛中找到更多帮助，因为这实际上更像是一种VB语言问题。

-Steve

Hi Folks,

Im working on converting a tool we use that communicates with a piece of equipment using TCP from VB6 to VS2005+.  It used to use the winsock.ocx, and with VS I'm using sockets.  I have been able to sucessfully trasmit a command to the equipment, but I am not able to get a response.  I am fairly new to TCP communications...

This is the old code (VB 6)

Public sender1 As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
Dim data As String
sender1.GetData data
(Mid$(data, i2 + 1, 1)

This is what I converted it to (unsucessfully!)

Dim data As String
frmMain.sender1.Receive(data)
(Mid$(data, i2 + 1, 1)

When I get a response, I get an exception about recieving null data... and if I change the data to "Dim data as String """, I get System.InvalidCastException occurred
  Message="Unable to cast object of type 'System.String' to type 'System.Collections.Generic.IList`1[System.ArraySegment`1[System.Byte]]'.".

I have also tried changing "data" to a byte array, but the problem with that is (Mid$(data, i2 + 1, 1), requires "data" to be a string.

Does anyone have any suggestions?

解决方案

I would use a byte array. Mid

requires string arguments, so I would use Array.CopyTo instead.

You may find more help in a VB forum, since this is actually more of a VB language question.

        -Steve

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