There are quite a few similar topics and issues around here and I follow this . But I get error.
My Code
@Override protected void onAct
I guess you imported the wrong Matrix class, you should import android.graphics.Matrix, not android.opengl.Matrix, please double check.
Change to this Bitmap rotatedBitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(),matrix, true);