Question

i try to rotate 3 imageViews (or better the Bitmaps behind them) every 10-100ms.
i do the rotation like this:

ImageView ivLoad;
Bitmap bMapLoad;

....

Matrix mat=new Matrix();
mat.reset();
mat.postScale(1.55f, 1.55f);
mat.postRotate((float)currentLoadDegree+(float)LoadDegree);
bMapLoad = Bitmap.createBitmap(bMapLoadgr, 0, 0, bMapLoadgr.getWidth(), bMapLoadgr.getHeight(), mat, true);
ivLoad.setImageBitmap(bMapLoad);
ivLoad.setScaleType(ScaleType.CENTER);

....

the first time i start the app everthing works fine.
second time also works
but the 3rd time i start the app it crashs with the following error:

03-27 10:01:09.234: E/AndroidRuntime(3603): java.lang.OutOfMemoryError
03-27 10:01:09.234: E/AndroidRuntime(3603):     at android.graphics.Bitmap.nativeCreate(Native Method)    
03-27 10:01:09.234: E/AndroidRuntime(3603):     at android.graphics.Bitmap.createBitmap(Bitmap.java:605)  
03-27 10:01:09.234: E/AndroidRuntime(3603):     at android.graphics.Bitmap.createBitmap(Bitmap.java:551)

after trying around a long time i found out that when i call System.exit(0) in the onDestroy methode everthing works.
now i don’t know if there would be a better way because on google a lot of peaople mean that System.exit(0) is unsafe.

so will i get problems with this?

Answer 1

You shouldn’t recreate the bitmap on every step of the rotation, instead you should just try to draw it rotated. That’s also possible with a Matrix (what you already use) and will avoid the excessive memory usage.

Android: How to rotate a bitmap on a center point