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Q96539: FOXTOOLS.FLL Calls to GetDC, GetDeviceCaps and ReleaseDC

Article: Q96539
Product(s): Microsoft FoxPro
Version(s): 2.5x 2.60 2.60a 3.00
Operating System(s): 
Keyword(s): kbcode
Last Modified: 14-AUG-1999

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
- Microsoft FoxPro for Windows, versions 2.5x, 2.6, 2.6a 
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SUMMARY
=======

The code below demonstrates how to use the FOXTOOLS.FLL library commands to call
the following Microsoft Windows application programming interface (API)
functions:

     GetDC()
     GetDeviceCaps()
     ReleaseDC()

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

The program first loads the FOXTOOLS.FLL library that is supplied with FoxPro
for Windows and creates some variables. It then retrieves the handle to the
display device and calls the GetDeviceCaps() function. Next, it displays the
width and height of the physical display in millimeters in two consecutive
windows that can be seen by clicking the left mouse button. Finally, it releases
the handle to the device context and the library.

     set library to sys(2004)+"foxtools.fll" additive

     * create variables to pass index to GetDeviceCaps()
     * these values are found in the WINDOWS.H file

     HORZSIZE = 4
     VERTSIZE = 6

     * get the handle to the device context

     gethdc = RegFN("GetDC","I","I")
     hdc = CallFN(gethdc,0)

     * get the screen size in millimeters

     getsize = RegFN("GetDeviceCaps","II","I")
     Hsize = CallFN(getsize,hdc,HORZSIZE)
     Vsize = CallFN(getsize,hdc,VERTSIZE)

     * display the results in two windows

     wait window "Width is: " + alltrim(str(Hsize)) + " mm"
     wait window "Height is: " + alltrim(str(Vsize)) + " mm"

     * release the handle to the device context

     releasehdc = RegFN("ReleaseDC","II","I")
     = CallFN(releasehdc,0,hdc)

     release library sys(2004)+"foxtools.fll"

REFERENCES
==========

Microsoft Windows Software Development Kit, "Programmer's Reference, Volume 2:
Functions," pages 350-354, 785

FOXTOOLS.WRI located in the C:\FOXPROW\GOODIES\FOXTOOLS subdirectory

WINDOWS.H located in the C:\C700\INCLUDE subdirectory

Additional query words: VFoxWin FoxWin 2.50 2.50a 2.50b FOXTOOLS SDK kbvfp300

======================================================================
Keywords          : kbcode 
Technology        : kbVFPsearch kbAudDeveloper kbFoxproSearch kbFoxPro260 kbFoxPro260a kbVFP300
Version           : 2.5x 2.60 2.60a 3.00

=============================================================================

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