Error Domain=NSCocoaErrorDomain Code=3840 JSON text did not start with array or object and option

数据请求失败

报错 Error Domain=NSCocoaErrorDomain Code=3840 "JSON text did not start with array or object and option to allow fragments not set." UserInfo={NSDebugDescription=JSON text did not start with array or object and option to allow fragments not set.

这是服务器端的问题 主要是服务器端返回的json格式不符合要求，让服务器解决