保存到手机的图像不会出现在图库中

Question

我的应用中人们保存到手机中的图片不仅会立即显示在“文件”中，也不会立即显示在他们的图库中。

@Override
protected String doInBackground(String... args) {
    // TODO Auto-generated method stub
    path = args[0];
    String idStr = path.substring(path.lastIndexOf('/') + 1);
    File filepath = Environment.getExternalStorageDirectory();
    File dir = new File (filepath.getAbsolutePath()
                + "/" + getString(R.string.app_name) + "/");
    dir.mkdirs();
    String fileName = idStr;
    Ion.with(getApplicationContext()).load(path)
          .write(new File(dir, fileName));
    return null;
}


@Override
protected void onPostExecute(String args) {
    // TODO Auto-generated method stub
    Toast.makeText(SlideImageActivity.this,  
                   getString(R.string.saved_in_folder)
                       + " "
                       + getString(R.string.app_name), 
                   Toast.LENGTH_SHORT
                  ).show();
    pDialog.dismiss();
}