NSDictionary *dic=[NSDictionary dictionaryWithObjectsAndKeys:[datas objectForKey:@"order_id"],@"order_id",_isgeval,@"geval_isanonymous",_store_desccredit,@"store_desccredit",_store_servicecredit,@"store_servicecredit",_store_deliverycredit,@"store_deliverycredit",userModel.key,@"key",s2,@"goods",nil];
goods参数在后台格式"{201:{geval_scores:0,geval_content:555}}";
http://stackoverflow.com/questions/6368867/generate-json-string-from-nsdictionary
里面有两个类别,一个是把字典转成json,另一个是把数组转成json。