Microsoft KB Archive/103214

{|
 * width="100%"|

Updating the Screen Without Flicker

 * }

Q103214

-

The information in this article applies to:


 * Microsoft Windows Software Development Kit (SDK) 3.1

-

SUMMARY
This article describes a technique for drawing to a window Device Context (DC) in such a way that the screen does not flicker. The technique is very simple and easy to implement.

Many applications written for the Microsoft Windows operating system maintain status information such as the current time in a small control window that flickers very annoyingly each time it's updated. All standard Windows controls flicker if updated at frequent intervals. The solution to this problem is to implement a simple control and use an off-screen device context (DC) to construct the image, which is then copied in total to the client area of the control window. The net result is a control that can be updated without causing any flicker.

FLICKER has window procedures for two controls--one of these flickers; the other one doesn't. The application creates an instance of each of these controls and updates the window text ten times every second to show how one flickers and the other doesn't. Both controls support the system text color, window background color, and the WM_SETTEXT and WM_SETFONT messages.

MORE INFORMATION
The following files are available for download from the Microsoft Download Center:

Flicker.exe

For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base:

"Q119591 How to Obtain Microsoft Support Files from Online Services" Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file.

Additional query words: kbfile softlib FLICKER.EXE

Keywords : kbfile kbsample kb16bitonly kbOSWin310 kbSDKWin16

Issue type : kbinfo

Technology : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310