Android Drawable、Bitmap、byte[]之间的转换
1、Drawable → Bitmap

　　Java代码
　

　　public static Bitmap drawableToBitmap(Drawable drawable) {　　Bitmap bitmap = Bitmap　　.createBitmap(　　drawable.getIntrinsicWidth(),　　drawable.getIntrinsicHeight(),　　drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888　　: Bitmap.Config.RGB_565);　　Canvas canvas = new Canvas(bitmap);　　//canvas.setBitmap(bitmap);　　drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());　　drawable.draw(canvas);　　return bitmap;　　}　　public static Bitmap drawableToBitmap(Drawable drawable) {　　Bitmap bitmap = Bitmap　　.createBitmap(　　drawable.getIntrinsicWidth(),　　drawable.getIntrinsicHeight(),　　drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888　　: Bitmap.Config.RGB_565);　　Canvas canvas = new Canvas(bitmap);　　//canvas.setBitmap(bitmap);　　drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());　　drawable.draw(canvas);　　return bitmap;　　}　　2、从资源中获取Bitmap　　Java代码　　Resources res=getResources();　　Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.pic);　　Resources res=getResources();　　Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.pic);　　3、Bitmap → byte[]　　Java代码　　private byte[] Bitmap2Bytes(Bitmap bm){　　ByteArrayOutputStream baos = new ByteArrayOutputStream();　　bm.compress(Bitmap.CompressFormat.PNG, 100, baos);　　return baos.toByteArray();　　}　　private byte[] Bitmap2Bytes(Bitmap bm){　　ByteArrayOutputStream baos = new ByteArrayOutputStream();　bm.compress(Bitmap.CompressFormat.PNG, 100, baos);　　return baos.toByteArray();　　}　　4、 byte[] → Bitmap　　Java代码　　private Bitmap Bytes2Bimap(byte[] b){　　if(b.length!=0){　　return BitmapFactory.decodeByteArray(b, 0, b.length);　　}　　else {　　return null;　　}　　}　　private Bitmap Bytes2Bimap(byte[] b){　　if(b.length!=0){　　return BitmapFactory.decodeByteArray(b, 0, b.length);　　}　　else {　　return null;　　}　　}