Microsoft KB Archive/28344

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PRB: PlayMetaFile Not as Fast as More Complex Technique

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Q28344

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The information in this article applies to:


 * Microsoft Windows Software Development Kit (SDK) versions 3.0, 3.1

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SYMPTOMS
The PlayMetaFile function is slower than using a loop that contains the EnumMetaFile and PlayMetaFileRecord commands.

CAUSE
PlayMetaFile takes longer because it plays the metafile records, and it also performs several additional steps:


 * 1) Verifies that its handle parameter points to a valid metafile.
 * 2) Locks the metafile.
 * 3) Saves all objects in the device context (pens, brushes, regions, etc.).
 * 4) Plays the metafile records.
 * 5) Restores all objects in the display context. PlayMetaFile will restore default objects if other restoration fails.
 * 6) Unlocks the metafiles.
 * 7) Deletes all objects created while playing the metafile.

To achieve this speed advantage, the callback function specified in EnumMetaFile would call only PlayMetaFileRecord. The actual speed of execution is determined by the amount of processing done in the EnumMetaFile callback function.

Additional query words: 3.00 3.10 no32bit

Keywords : kb16bitonly

Issue type :

Technology : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK300 kbWinSDK310