请教TDSServerModule如何返回纯字符串？

[denept]

function TServerMethods1.getUserInfo: string;
begin
Result:='{"return_code": "0","token": "public","list": [{"title": "服务器端版本","value": "0.1.1"},{"title": "客户端最新版本","value": "1001"},{"title": "当前队列任务数量","value": 0}]}';
end;
访问
http://localhost:8080/datasnap/rest/TServerMethods1/getUserInfo
返回如下数据：
{"result":["{\"return_code\": \"0\",\"token\": \"public\",\"list\": [{\"title\": \"\u670D\u52A1\u5668\u7AEF\u7248\u672C\",\"value\": \"0.1.1\"},{\"title\": \"\u5BA2\u6237\u7AEF\u6700\u65B0\u7248\u672C\",\"value\": \"1001\"},{\"title\": \"\u5F53\u524D\u961F\u5217\u4EFB\u52A1\u6570\u91CF\",\"value\": 0}]}"]}

我想返回这种格式：
{"return_code": "0","token": "public","list": [{"title": "服务器端版本","value": "0.1.1"},{"title": "客户端最新版本","value": "1001"},{"title": "当前队列任务数量","value": 0}]}

请问如何实现？