How to update the data values while editing mode in WPF DataGrid (SfDataGrid)?

this.dataGrid.CellRenderers.Remove("TextBox");
this.dataGrid.CellRenderers.Add("TextBox", new GridCellTextBoxRendererExt(dataGrid));
 
public class GridCellTextBoxRendererExt : GridCellTextBoxRenderer
{
        RowColumnIndex RowColumnIndex;
        SfDataGrid DataGrid { get; set; }
        string newvalue = null;
 
        public GridCellTextBoxRendererExt(SfDataGrid dataGrid)
        {
            DataGrid = dataGrid;
        }
        
        public override void OnInitializeEditElement(DataColumnBase dataColumn, TextBox uiElement, object dataContext)
        {
            base.OnInitializeEditElement(dataColumn, uiElement, dataContext);
          
            uiElement.TextChanged += UiElement_TextChanged;
            this.RowColumnIndex.ColumnIndex = dataColumn.ColumnIndex;
            this.RowColumnIndex.RowIndex = dataColumn.RowIndex;
        }           
 
        private void UiElement_TextChanged(object sender, TextChangedEventArgs e)
        {
            var textbox = (e.OriginalSource as TextBox);
            if (textbox.IsFocused)
            {
                newvalue = (e.OriginalSource as TextBox).Text;
                UpdateValues(this.RowColumnIndex.RowIndex, this.RowColumnIndex.ColumnIndex);
            }
        }     
 
        private void UpdateValues(int rowIndex, int columnIndex)
        {
            string editEelementText = newvalue;
            columnIndex = this.DataGrid.ResolveToGridVisibleColumnIndex(columnIndex);
            if (columnIndex < 0)
                return;
            var mappingName = DataGrid.Columns[columnIndex].MappingName;
            var recordIndex = this.DataGrid.ResolveToRecordIndex(rowIndex);
            if (recordIndex < 0)
                return;
            if (DataGrid.View.TopLevelGroup != null)
            {
                var record = DataGrid.View.TopLevelGroup.DisplayElements[recordIndex];
                if (!record.IsRecords)
                    return;
                var data = (record as RecordEntry).Data;
                data.GetType().GetProperty(mappingName).SetValue(data, editEelementText);
            }
            else
            {
                var record1 = DataGrid.View.Records.GetItemAt(recordIndex);
                record1.GetType().GetProperty(mappingName).SetValue(record1, editEelementText);
            }
        }
}