DOCUMENT:Q181946 03-MAR-1998 [vbwin] TITLE :HOWTO: Create a NetDDE Client and Server in Visual Basic PRODUCT :Microsoft Visual Basic for Windows PROD/VER:WINDOWS:4.0,5.0 OPER/SYS:WINDOWS KEYWORDS:VB4ALL VB4WIN vb5all vb5howto VBKBNet vbwin ====================================================================== --------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 5.0 - Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 16-bit and 32-bit, for Windows, version 4.0 --------------------------------------------------------------------- SUMMARY ======= This article demonstrates how to use NetDDE to communicate with a Microsoft Visual Basic application on a remote computer. This article assumes that you are familiar with DDE communications and demonstrates creating both the client and server applications in Visual Basic. MORE INFORMATION ================ In order to establish a link to a remote application, a DDE share must be created on the remote computer. A DDE share consists of a Share Name, Application name, and a Topic. Shares may be created and edited using the DDE Share Manager (DDESHARE.EXE), which may be found in the directory on NT 4.0. For Windows 95 and Windows For Workgroups, the Network DDE Share Manager can be found in the Windows for Workgroups Resource Kit. Creating the Visual Basic NetDDE Server --------------------------------------- 1. Start Visual Basic and create a new Standard EXE application. Form1 is created by default. 2. Place a Textbox (Text1) on Form1 and set the Text Property to "The DDE Server is Running." 3. Change the LinkMode Property of Form1 to "1 - Source." 4. Select Project1 Properties from the Project menu, select the Make tab, and then change the application title to DDESRV. 5. Compile and save the application and name it DDESRV.EXE. 6. Install the application on a computer on your network that you want to use as the Server. Creating the DDE Share on the Server ------------------------------------ 1. Start the DDE Share Manager Application on the Computer designated as the Server. Select Run from the Windows Start menu, and then run DDESHARE. 2. Select "DDE Shares" from the "Shares" menu. A list of shares that have previously been set up will be displayed in the list box. 3. Click the "Add a Share" button. 4. Enter "DDETEST$" in the "Share Name" textbox. NOTE: When creating the share name it is not necessary to place a trailing "$," although it is conventional to do so. 5. Enter the following values in the corresponding Application and Topic Text boxes: Application Name Topic Name ------------------- --------------- oldstyle DDESRV.DDE Form1 newsytle DDESRV.OLE Form1 static DDESRV Form1 NOTE: The DDESHARE utility for WFW/WIN95 only supports defining one Application and Topic name each. Use the static Application and Topic names from the list above. 6. Click OK to close the DDE Share Properties dialog. IMPORTANT: Due to a bug in the DDE Share Utility, when exiting the DDE Share application, a new serial number is created for the Share but is not updated in the Trusted DDE Shares section of the registry; therefore, the next two steps are very important. 7. Select the DDETEST$ share in the list and click on the "Trust Share" button. 8. Make sure that "Initiate to Application Enable" is selected and then click the "SET" button. 9. Press OK on both open dialogs and then exit the DDE Share Utility. Creating and Testing the Visual Basic NetDDE Client --------------------------------------------------- 1. Start a new Standard EXE project in Visual Basic. Form1 is created by default. 2. Add a CommandButton to Form1. Change the following properties: Name: cmdConnect Caption: Connect 3. Add a Text box to Form1 and name it txtData. 4. Paste the following code into the Declarations Section of Form1: NOTE: Replace the with the appropriate computer name where the DDE SRV application will be running. Private Sub cmdConnect_Click() txtData.linkMode = vbLinkNone txtData.linkTopic = "\\\NDDE$|DDETEST$ txtData.LinkItem = "Text1" txtData.LinkMode = vbLinkManual txtData.LinkRequest End Sub 5. Start the DDESRV application on the Network computer acting as the DDE Server. 6. Press the F5 key to run this client within the Visual Basic 5.0 IDE. 7. Click the Command button labeled "Connect" and note that the string "The DDE Server is Running" appears within the txtData Text Box. REFERENCES ========== For additional information, please see the following article in the Microsoft Knowledge Base: ARTICLE-ID: Q114089 TITLE : Using the Windows NT NetDDE Share Manager ====================================================================== Keywords : VB4ALL VB4WIN vb5all vb5howto VBKBNet vbwin Version : WINDOWS:4.0,5.0 Platform : WINDOWS Issue type : kbhowto ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1998.