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caching – Android: ScrollView and drawing cache?

Posted by: admin June 15, 2020 Leave a comment

Questions:

Are the views that get scrolled off of ScrollView automatically cached by the drawing cache? I’m not quite sure i understand the API documentation.

How to&Answers:

int PERSISTENT_ALL_CACHES Used to indicate that all drawing caches should be kept in memory.

int PERSISTENT_ANIMATION_CACHE Used to indicate that the animation drawing cache should be kept in memory.

int PERSISTENT_NO_CACHE Used to indicate that no drawing cache should be kept in memory.

int PERSISTENT_SCROLLING_CACHE Used to indicate that the scrolling drawing cache should be kept in memory.


Use these in

public void setPersistentDrawingCache (int drawingCacheToKeep) 

which indicates what types of drawing caches should be kept in memory after they have been created.


Example

 setPersistentDrawingCache(ViewGroup.PERSISTENT_SCROLLING_CACHE);
 setAlwaysDrawnWithCacheEnabled(true); // call this method 
 //to start (true) and stop (false) using the drawing cache
 //when you perform performance sensitive operations, like scrolling or animating.