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.

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

Flicker.exe (http://download.microsoft.com/download/platformsdk/demo6/3.1/w31/en-us/flicker.exe)

For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.