如何在WebAPI C＃中以JSON对象格式而不是JSON数组检索结果

Question

I have following simple code which is giving list of employee , i have not added any formatter getting result in json array format.

I want it as a json object which has one defined key , how can i achieve this?

 public HttpResponseMessage GetEmployee([FromUri(Name ="")]FilterEntity filters)
 {
      try
      {
           string contentType=Request.Headers.Accept.ToString();        
           if (String.Equals(contentType, Ecng_APIMsg.ContentType))
           {
                var empDetails = _empService.GetEMployee(filters.systemId, filters.pageIndex, filters.pageSize, filters.sortDirection);
                if (empDetails != null)
                { 
                     return Request.CreateResponse(HttpStatusCode.OK, empDetails);
                }
           }
      }
      catch(Exception ex)
      {
      }
 }

output-

[
  {
    "Id": 43,
    "EmpId": 11
  },
  {
    "Id": 42,
    "EmpId": 12
  }
]

expected

"data" : [
  {
    "Id": 43,
    "EmpId": 11
  },
  {
    "Id": 42,
    "EmpId": 12
  }
]

data must be there as a key of that json object. I tried like below code to achieve this which is not working I'm missing something here -

var response = Request.CreateResponse(HttpStatusCode.OK, empDetails);  
   response.Content = new StringContent(response.ToString(), System.Text.Encoding.UTF8, "application/json");
   return response;

Answer 1

Hope in your code " var empDetails " is a List<Employee> (List of Employee class)

As per your JSON structure i guess your Employee class would be like below

public class Employee
{
    public int Id{ get; set; }
    public int EmpId{ get; set; }
}

That's the reason when you are returning the json structure, it returns as

[
  {
    "Id": 43,
    "EmpId": 11
  },
  {
    "Id": 42,
    "EmpId": 12
  }
]

if you want your json data need to be changed as you expect, then create another class named as EmployeeVM

public class EmployeeVM
{
    public List<Employee> data{ get; set; }        
}

and construct your EmployeeVM from your code and return EmployeeVM as json from your web api.

Answer 2

create another class as below,

public class clsDemo
{
    public Object data { get; set; }
}

use,

clsDemo ObjDemo = new clsDemo();
ObjDemo.data = empList;//Your 'empDetails'
String result = JsonConvert.SerializeObject(ObjDemo);

Answer 3

You could create an object to wrap the collection. Using an anonymous object can be done as a quick and simple solution.

return Request.CreateResponse(HttpStatusCode.OK, new { data = empDetails });

Based on original example in question the above update to the code would yield

{
  "data" : [
    {
      "Id": 43,
      "EmpId": 11
    },
    {
      "Id": 42,
      "EmpId": 12
    }
  ]
}