Drawable、Bitmap、byte[]其间的转换（转载）

Drawable、Bitmap、byte[]之间的转换（转载）
1.Drawable → 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); 
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight()); 
        drawable.draw(canvas); 
        return bitmap; 
} 


2.Bitmap → byte[]
private byte[] Bitmap2Bytes(Bitmap bm){ 
    ByteArrayOutputStream baos = new ByteArrayOutputStream();   
    bm.compress(Bitmap.CompressFormat.PNG, 100, baos);   
    return baos.toByteArray(); 
   }

3.byte[] → Bitmap
private Bitmap Bytes2Bimap(byte[] b){ 
            if(b.length!=0){ 
                return BitmapFactory.decodeByteArray(b, 0, b.length); 
            } 
            else { 
                return null; 
            } 
      }