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Q80784: DOC: Suggested Changes to the DEVCAPS2 Sample App

Article: Q80784
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1
Operating System(s): 
Keyword(s): kbdocfix kbSDKWin16
Last Modified: 16-JUN-1999

3.00 3.10
WINDOWS
kbprg kbfile

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
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SUMMARY
=======

DEVCAPS2 is a sample application developed for the Windows environment by
Charles Petzold. DEVCAPS2 demonstrates how to retrieve various capabilities of a
printer or display device. This sample is included in the book "Programming
Windows Version 3," published by Microsoft Press.

This article describes a change that should be made to the code in DEVCAPS2, and
also to any application based on DEVCAPS2. This change works around a problem in
calling the DeviceMode() API.

MORE INFORMATION
================

Problem Description
-------------------

When the user selects DeviceMode from the File menu and modifies the printer
settings in the dialog box, the unmodified version of DEVCAPS2 does not update
the WIN.INI file with the changed information. Similarly, any changes to printer
settings made using the Control Panel are not reflected in the dialog box in
DEVCAPS2.

The DeviceMode menu item is designed to allow the user to modify any printer
settings globally, for all applications. Any application that uses the
DeviceMode dialog box should use the new printer settings. In addition, the
application should write the new printer settings into the WIN.INI file.

Resolution
----------

Because the DEVCAPS2 program calls the DeviceMode() API with incorrect
parameters, it exhibits the behavior described above. The following code appears
in the DEVCAPS2.C file starting at line 176:

     szOutput = strtok(szDriver,", ");
     strcat(strcpy(szDriverFile, szDriver), ".DRV");

The code above sets szOutput equal to the name of the device driver (for example,
"EPSON9") rather than to the output port (for example, "LPT1:"). To correct this
problem, modify the code to add an additional call to the strtok function, as in
the following code:

     szOutput = strtok(szDriver, ", ");
     szOutput = strtok(NULL, ", ");
     strcat(strcpy(szDriverFile, szDriver), ".DRV");

After the modification, szOutput points to the output port. In the subsequent
call to DeviceMode(), the parameters are correct, and the function works as
expected.

In Windows version 3.1, applications should call ExtDeviceMode() instead of
DeviceMode().

Additional query words: 3.00 3.10

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Keywords          : kbdocfix kbSDKWin16 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Version           : WINDOWS:3.1

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