Drawable转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;
    }