ACC2000: How to Convert Twips to Pixels

• Microsoft Access 2000

SUMMARY

Because Microsoft Access stores dimension/location properties as twips, in certain cases you may have to convert twips to pixels, such as when you call a Windows API function. This article shows you how to do this.

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MORE INFORMATION

You can use the following ConvertTwipsToPixels() function to convert twips to pixels. Note that pixels are not always square (the height and width are not the same); therefore, it is necessary to pass in the desired "direction" to use (horizontal or vertical).

1. Create a new module and type the following in the Declarations section:

   
   Option Explicit
   
   Declare Function GetDC% Lib "User32" (ByVal hw%)
   Declare Function ReleaseDC% Lib "User32" (ByVal hw%, ByVal hDC%)
   Declare Function GetDeviceCaps% Lib "Gdi32" (ByVal hDC%, _
      ByVal iCapability%)
   
   Const WU_LOGPIXELSX = 88
   Const WU_LOGPIXELSY = 90
    

   NOTE: You may have some Microsoft Windows API functions defined in an existing Microsoft Access library; therefore, your declarations may be duplicates. If you receive a duplicate procedure name error message, remove or comment out the declarations statement in your code.



2. Type the following procedures:




Function ConvertTwipsToPixels (lngTwips as Long, _
   lngDirection as long) As Long

   'Handle to device
   Dim lngDC as long                        
   Dim lngPixelsPerInch as Long
   Const nTwipsPerInch = 1440
   lngDC = GetDC(0)
   
   If (lngDirection = 0) Then       'Horizontal
      lngPixelsPerInch = GetDeviceCaps(lngDC, WU_LOGPIXELSX)
   Else                            'Vertical
      lngPixelsPerInch = GetDeviceCaps(lngDC, WU_LOGPIXELSY)
   End If
   lngDC = ReleaseDC(0, lngDC)
   ConvertTwipsToPixels = (lngTwips / nTwipsPerInch) * lngPixelsPerInch

End Function

Function ShowConvert()
   Dim lngOldTwips As Long
   lngOldTwips = 2377
   ShowConvert = ConvertTwipsToPixels(lngOldTwips, 0)
End Function 

OldTwips = 2377
NewPixels = ConvertTwipsToPixels(OldTwips, 0) 

Additional query words: inf

Keywords : kbprg kbdta
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbinfo