DOCUMENT:Q128237 06-NOV-1999 [win16sdk] TITLE :PRB: Polyline Fails with NULL Clipping Region PRODUCT :Microsoft Windows Software Development Kit PROD/VER:WINDOWS:3.1 OPER/SYS: KEYWORDS:kb16bitonly ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows Software Development Kit (SDK) 3.1 ------------------------------------------------------------------------------- SYMPTOMS ======== The Polyline API will return a failure code if called on a DC that has a NULL clipping region selected. One situation in which this can occur is when Polyline is used to draw into a DC for a window that is completely obscured by another window. RESOLUTION ========== Check to see if the clipping region is NULL before calling Polyline and testing its return value. STATUS ====== This behavior is by design on Windows 3.1. This behavior does not occur on Windows NT or on Windows 95. Additional query words: 3.10 no32bit Polygon fails hidden ====================================================================== Keywords : kb16bitonly Technology : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310 Version : WINDOWS:3.1 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 1999.