How to copy cell value of entire GridTemplateColumn in WPF DataGrid (SfDataGrid)?

this.SampleDataGrid.GridCopyPaste = new CustomCopyPaste(this.SampleDataGrid);
public class CustomCopyPaste : GridCutCopyPaste
{
    public CustomCopyPaste(SfDataGrid DataGrid)
        : base(DataGrid)
    {
 
    }
    protected override void CopyCell(object record, GridColumn column, ref System.Text.StringBuilder text)
    {
 
        if (this.dataGrid.View == null)
            return;
 
        object copyText = null;
 
        if (column is GridUnBoundColumn)
        {
            var unboundValue = this.dataGrid.GetUnBoundCellValue(column, record);
            copyText = unboundValue != null ? unboundValue.ToString() : string.Empty;
        }
        else
        {
            if (this.dataGrid.GridCopyOption.HasFlag(GridCopyOption.IncludeFormat))
                copyText = this.dataGrid.View.GetPropertyAccessProvider().GetFormattedValue(record, column.MappingName);
            else if (column is GridTemplateColumn && column.MappingName == "Value")
            {
                var dataItem = record as DataItem;
                if (dataItem.ItemType == 1)
                {
                    if (dataItem.ItemShortName <= 200)
                    {
                        var nameValuePair = (dataGrid.DataContext as SampleViewModel).NameValuePair;
                        copyText = nameValuePair[dataItem.StringValue].Name;
 
                    }
                    else if (dataItem.ItemShortName <= 400)
                    {
                        var nameValuePair = (dataGrid.DataContext as SampleViewModel).NameValuePair1;
                        copyText = nameValuePair[dataItem.StringValue].Name;
                    }
                    else
                    {
                        copyText = dataItem.ItemShortName.ToString() + "" + "th" + " Mango";
                    }
                }
                else if (dataItem.ItemType == 2)
                {
                    copyText = dataItem.DateTimeValue;
                }
                else
                {
                    copyText = dataItem.ItemShortName;
                }
            }
            else
                copyText = this.dataGrid.View.GetPropertyAccessProvider().GetValue(record, column.MappingName);
        }
        var copyargs = this.RaiseCopyGridCellContentEvent(column, record, copyText);
        if (!copyargs.Handled)
        {
            if (this.dataGrid.Columns[leftMostColumnIndex] != column || text.Length != 0)
                text.Append('\t');
 
            text.Append(copyargs.ClipBoardValue);
        }
    }
}