Microsoft KB Archive/32919

MSJ BLOWUP: Capture Screen Image to Clipboard

PSS ID Number: Q32919 Article last modified on 04-16-1991

MS-DOS

Summary: The following is a summary of a program found in the “Microsoft Systems Journal” and in the Software/Data Library: Issue: July 1987, Vol. 2, No. 3, pages 51-58 Title: “BLOWUP: A Windows Utility for Viewing and Manipulating Bitmaps” Author: Charles Petzold Keyword: BLOWUP BLOWUP can be found in the Software/Data Library by searching on the keyword BLOWUP, the Q number of this article, or S10000. BLOWUP was archived using the PKware file-compression utility. The BLOWUP program demonstrates how to manipulate and view bitmaps. It does this by allowing you to select any area of the screen; it then transfers that bitmap to the Clipboard and expands or shrinks the bitmap to fit into the client area of the blowup window. The following text is taken from the cover of the “Microsoft Systems Journal”: Using bitmaps in the Windows environment is not trivial. The programmer must understand memory display contexts, how bitmaps are scaled, and how to transfer bitmaps via the clipboard. BLOWUP, a useful Windows tool, can capture and manipulate any part of the Windows display.

More Information: Some of the Windows programming concepts that are used in BLOWUP are: 1. Capturing images from the screen 2. Capturing the mouse to use it to select an area outside your window 3. Painting outside of a window’s client area 4. Creating a bitmap 5. Copying a bitmap to the Clipboard 6. Installing yourself on the Clipboard viewing chain 7. Stretching the bitmap and displaying it in your client area