Formatting JSON as an Array in ASP.NET MVC

Question

I'm having a hard time in returning the formatted JSON as an array. My current code already returns JSON as an array but I want to get rid of these bracket first [] to get my desired output.

Controller

public JsonResult GenerateGanttChart()
    {
        SPMS_GanttChartLayers ddl = new SPMS_GanttChartLayers();
        var data = ddl.GenerateGanttChart();
        return Json(data, JsonRequestBehavior.AllowGet);
    }

Layer

public IEnumerable<SPMS_GanttChartRootModel> GenerateGanttChart()
    {
        List<SPMS_GanttChartModel> child_data = new List<SPMS_GanttChartModel>();
        {
            using (SqlConnection con = new SqlConnection(Conn.MyConn()))
            {
                SqlCommand com = new SqlCommand("dbo.sp_SPMS_GanttChart 7078, 1", con);
                con.Open();
                SqlDataReader reader = com.ExecuteReader();
                while (reader.Read())
                {
                    SPMS_GanttChartModel value = new SPMS_GanttChartModel();
                    value.id = Convert.ToInt32(reader.GetValue(0));
                    value.start_date = Convert.ToString(reader.GetValue(1));
                    value.duration = Convert.ToInt32(reader.GetValue(2));
                    value.text = Convert.ToString(reader.GetValue(3));
                    child_data.Add(value);
                }
            }

        }
        List<SPMS_GanttChartRootModel> array = new List<SPMS_GanttChartRootModel>();
        {
            SPMS_GanttChartRootModel value = new SPMS_GanttChartRootModel();
            value.data = child_data;
            array.Add(value);
        };
        return array;
    }

Current Output

[{
"data": [{
    "id": 1,
    "start_date": "11/07/2017 08:00:00 AM",
    "duration": 23,
    "text": "Project #1"
}, ... ]
}]

Desired Output

{
"data": [{
    "id": 1,
    "start_date": "11/07/2017 08:00:00 AM",
    "duration": 23,
    "text": "Project #1"
}, ... ]
}

Answer 1

Currently you are returning a List<SPMS_GanttChartRootModel> from your GenerateGanttChart method.

Return the SPMS_GanttChartRootModel object.

SPMS_GanttChartRootModel value = new SPMS_GanttChartRootModel();
value.data = child_data;
return value;

Also make sure your method's return type is SPMS_GanttChartRootModel now

public SPMS_GanttChartRootModel  GenerateGanttChart()
{
    var child_data = new List<SPMS_GanttChartModel>();
    {
        //your existing code to populate this collection
    };

     var value = new SPMS_GanttChartRootModel();
     value.data = child_data;
     return value;
}

and in your action method, pass this single object to the Json method

public JsonResult GenerateGanttChart()
{
    var ddl = new SPMS_GanttChartLayers();
    var data = ddl.GenerateGanttChart();
    return Json(data, JsonRequestBehavior.AllowGet);
}