PRB: Network DDE Requests Fail from Visual FoxPro (149639)


The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 3.0
  • Microsoft Visual FoxPro for Windows 3.0b
  • Microsoft Visual FoxPro for Windows 5.0
  • Microsoft Visual FoxPro for Windows 5.0a
  • Microsoft Visual FoxPro for Windows 6.0
This article was previously published under Q149639

SYMPTOMS

From Visual FoxPro, you can use Network DDE to make a connection to a dynamic data exchange (DDE) enabled application over the network, but all requests are ignored by the application. The conversation cannot be terminated.

CAUSE

Visual FoxPro DDE commands are designed to talk only to local DDE servers, not DDE servers located over a network.

STATUS

This behavior is by design.

WORKAROUND

Use Network DDE by way of Windows API calls, such as DDEInitiate.

MORE INFORMATION

The following example requires use of Chat which is located in the Network group in Windows for Workgroups.

Steps to Reproduce Behavior

The following example tries to start a Network DDE conversation with Winchat, which is located on a remote computer. Before starting the conversation, load Winchat on both client and server computers to enable NetDDE. On the client computer, close down Winchat. On the server computer, minimize Winchat. Starting a Network DDE conversation in Visual Basic 4.0 Enterprise Edition will 'ring' the WINCHAT phone.

  1. In the Visual FoxPro Command window, type: 
          nsyschan=DdeInitiate("\\server\ndde$\chat$","chat")
    The command is accepted and returns a positive channel number but the WINCHAT phone doesn't ring.
  2. In the Command window, type: 
          ltermchan=DdeTerminate(nsyschan)
    The command returns false (.F.), and you cannot close the channel.
Modification Type:MajorLast Reviewed:5/12/2003
Keywords:KB149639
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