Drawable、Bitmap、byte[]之间的转换

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);
        //canvas.setBitmap(bitmap);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        return bitmap;
}
2.从资源中获取Bitmap

Resources res=getResources();

Bitmap bmp=BitmapFactory.decodeResource(res, R.drawable.pic);
3.Bitmap → byte[]

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

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