Q22242: PRB: Area Around Text and Remainder of Window Different Colors

Article: Q22242
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1,95; winnt:3.5,3.51,4.0
Operating System(s): 
Keyword(s): kbOSWinNT350 kbOSWinNT351 kbOSWinNT400 kbOSWin95 kbSDKWin16
Last Modified: 11-MAY-2001

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The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
- Microsoft Win32 Application Programming Interface (API), used with:
   - Microsoft Windows NT Server versions 3.5, 3.51, 4.0 
   - Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 
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SYMPTOMS
========

When text is painted into a window, an area around the text is a different color
than the remainder of the window.

CAUSE
=====

The area around the text is painted with a solid color while the remainder of
the window is painted using a dithered color.

RESOLUTION
==========

To make the area around the text and the remainder of the window have the same
color, perform one of the following two steps:

- Use a solid color for the window background, and use the same color for the
  text background. To ensure that a color is a solid color, use the
  GetNearestColor function. This function returns the nearest solid color
  available to represent the specified color.

  -or-

- Call the SetBkMode function to specify TRANSPARENT mode for the text. Doing
  so prevents Windows from painting the area behind the text. The window
  background color shows through instead.

STATUS
======

This behavior is by design.

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

By default, when an application paints text into its window, Windows fills the
area around the character with the current background color. Windows always uses
a solid color for this purpose.

When an application registers a window class, it specifies a handle to a brush
that Windows uses to paint the window background. On some output devices,
brushes can create dithered colors. On one of these devices, the area behind
painted text might have a different color than the remainder of the window.

The following code specifies the window background color:

     #define ELANGREEN  0x003FFF00
     pTemplateClass->hbrBackground = CreateSolidBrush((DWORD)ELANGREEN);

The following code specifies the color used to paint around text and draws some
text into a device context:

     #define SZ -1
     SetBkColor(hDC, (DWORD)ELANGREEN);
     DrawText(hDC, (LPSTR)"text", SZ, (LPRECT)&Rect, DT_BOTTOM);

The color used to paint the area around the text has a yellow cast, which gives
it a slightly different appearance than the window background color.

A brush may be able to represent a wider color range than the solid colors
because a brush covers an area while a solid color may be used to paint
nominal-width lines (for example, lines that are one device unit wide) that must
be the same color at all locations and angles. Therefore, the device-driver
writer has the option of providing dithered colors for brushes, but has no such
freedom when it comes to the solid colors for drawing lines.

Additional query words: 3.00 3.10 3.50 4.00 win16sdk

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Keywords          : kbOSWinNT350 kbOSWinNT351 kbOSWinNT400 kbOSWin95 kbSDKWin16 
Technology        : kbAudDeveloper kbSDKSearch kbWin32sSearch kbWin32API kbWinSDKSearch
Version           : WINDOWS:3.1,95; winnt:3.5,3.51,4.0
Issue type        : kbprb

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