Bitmap與Drawable之間的相互轉換
Bitmap轉Drawable:
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.a6);
mDrawable = new BitmapDrawable(mBitmap);
Drawable轉換Bitmap:
BitmapDrawable mBitmapDrawable = (BitmapDrawable) mDrawable;
mBitmapDrawable.getBitmap() ;