如何在不泄露上下文的情况下在AsyncTask中显示AlertDialog？

public class MyTask extends AsyncTask<Void, Void, Void> {
    private Context mContext;

    public MyTask(Context context) {
        mContext = context;
    }

    @Override
    protected Void doInBackground(Void... params) {
        // 执行后台任务
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        super.onPostExecute(result);
        
        // 在需要显示AlertDialog的地方
        AlertDialog.Builder builder = new AlertDialog.Builder(mContext);
        builder.setTitle("提示");
        builder.setMessage("这是一个AlertDialog示例");
        builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // 点击确定按钮的回调操作
            }
        });
        
        AlertDialog alertDialog = builder.create();
        alertDialog.show();
    }
}