[CLOSED] dynamic columns to gridpanel not showing up

[sharmav1]

I have a gridpanel which has few columns added in the html markup and one column added dynamically, but the dynamic column does not show up.
Please guide me what's wrong I am doing here:

View code:

X.FormPanel().DefaultButton("btnTestDynamic").Layout(LayoutType.HBox)
            
            
            .Buttons(
                X.Button().ID("btnTestDynamic").Text("Add").Listeners(l => { l.Click.Handler = "Add()"; }),
                
            ).ButtonAlign(Alignment.Center),
            
            X.GridPanel().Layout(LayoutType.Fit).ID("testGrid")
                .Store
                (
                    X.Store().ID("testStore")
                    .AutoLoad(false)
                    .Model
                    (
                        X.Model()
                        .Fields
                        (
                            new ModelField("Id"),                           
                            new ModelField("JoiningDate", ModelFieldType.Date)
                            
                            )
                        )
                )
                .ColumnModel
                (
                    X.Column().Text("Id").DataIndex("Id").Hidden(true),
                    X.Column().Text("Joining Date").DataIndex("JoiningDate")
        
                )
                .View(X.GridView().StripeRows(true).TrackOver(true))
                .SelectionModel(X.RowSelectionModel().Mode(SelectionMode.Single))

JS Code

function Add()
{
    
    Ext.net.Mask.show({ msg: 'Loading data..});
    $.ajax({
        url: "/Home/AddGridColumn",
        data: JSON.stringify({ testData: selectedValues }),
        async: false,
        type: "POST",
        contentType: 'application/json',
        success: function (result) {
            
                Ext.net.Mask.hide();
                App.testGrid.getStore().loadData(result.result);
                App.testGrid.getView().refresh();
                
            
        }
    });
}

CodeBehind:

public ActionResult AddGridColumn(string[] testData)
        {
          
            using (var uow = _uow.Create())
            {
                var finalData = GetJoinees(testData);
                if (finalData .Count() > 0)
                {
                    DataTable myDt = ConverDataToDatatable(finalData);
                    
                    GridPanel grid = X.GetCmp<GridPanel>("testGrid");
                    Store store = X.GetCmp<Store>("testStore");
                    
                   
                            foreach (DataRow row in myDt.Rows)
	                        {
                                
                                for (int j = 0; j < myDt.Columns.Count; j++)
                                {
                                    if (myDt.Columns[j].ColumnName == "UserDetail")
                                    {
                                        string[] splitColData = row[myDt.Columns[j].ColumnName].ToString().Split('_');
                                        if (splitColData.Count() > 0)
                                        {
                                            string userName = splitColData[0];
                                            DateTime JoinedOn = Convert.ToDateTime(splitColData[1]);
                                            
                                            ModelField fieldJoinedOn = new ModelField("Joined On", ModelFieldType.Date);
                                            store.AddField(fieldJoinedOn);
                                            

                                            Column gridCol = new Column();
                                            gridCol.Text = userName;
                                            

                                            ComponentColumn columnJoinedOn = new ComponentColumn();
                                            columnJoinedOn.Text = "Completed On";
                                            columnJoinedOn.DataIndex = completedOnFieldName;
                                            columnJoinedOn.Editor = true;
                                            DateField dtJoinedOn = new DateField();
                                            dtJoinedOn.Value = completedOn;
                                            columnCompletedOn.Component.Add(dtJoinedOn);


                                            
                                            gridCol.Columns.Add(columnJoinedOn);

                                            grid.AddColumn(gridCol);

                                            
                                        }

                                    }
                                    
                                }
	                        }

                    
                    var result = finalData;
                    return this.Direct(result);
                }
                else
                {
                    var result = "Error";
                    return this.Direct(result);
                }
            }


        }

Thanks