@Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        Log.v("msg", "sdf");
        doNext(requestCode, grantResults);
    }

private void doNext(int requestCode, int[] grantResults) {
        if (requestCode == 0x123) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission Granted
                Log.v("msg", "允许");
            } else {
                // Permission Denied
                Log.v("msg", "不允许");
            }
        }
    }
  if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
                        != PackageManager.PERMISSION_GRANTED) {
                    //申请WRITE_EXTERNAL_STORAGE权限
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                            0x123);
                }