Android Drawable、Bitmap、byte[]之间的转换

转自http://blog.csdn.net/june5253/article/details/7826597

1、Bitmap-->Drawable

    Bitmap drawable2Bitmap(Drawable drawable) {  
        if (drawable instanceof BitmapDrawable) {  
            return ((BitmapDrawable) drawable).getBitmap();  
        } else if (drawable instanceof NinePatchDrawable) {  
            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;  
        } else {  
            return null;  
        }  
    }

2、从资源中获取的Drawable-->Bitmap

Bitmap bitmap=BitmapFactory.decodeResource(res,R.drawable.pic);

3、Bitmap-->Drawable

Drawable bitmap2Drawable(Bitmap bitmap){
  new BitmapDrawable(bitmap);  
}

4、Bitmap-->byte[]

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

5、byte[]-->Bitmap

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