Merge Merging GridView Header Columns Multiple Headers ASP.NET

For this you need to create GridView header row in RowCreated Event

<asp:GridView ID="grvMergeHeader" runat="server" 

              AutoGenerateColumns="False" 

              DataSourceID="SqlDataSource1" 

              OnRowCreated="grvMergeHeader_RowCreated">

<Columns>

<asp:BoundField DataField="DepartMentID" HeaderText="DepartMentID"/>

<asp:BoundField DataField="DepartMent" HeaderText="DepartMent"/>

<asp:BoundField DataField="Name" HeaderText="Name"/>

<asp:BoundField DataField="Location" HeaderText="Location"/>

</Columns>

</asp:GridView>

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 

ConnectionString="<%$ ConnectionStrings:ConnectionString %>"

SelectCommand="SELECT [DepartMentID], [DepartMent], [Name], 

              [Location] FROM [Employee]">

</asp:SqlDataSource>

Now In Code behind, in RowCreated Event of grid view i m creating a new gridview row of header type and than in this row i m adding 2 cells 

C# CODE

---

protected void grvMergeHeader_RowCreated(object sender, GridViewRowEventArgs e)
{
        if (e.Row.RowType == DataControlRowType.Header)
        {

Row HeaderGridRow = new GridViewRow(0, 0, DataContr
GridView HeaderGrid = (GridView)sender;
            GridVie
wolRowType.Header, DataControlRowState.Insert);
            TableCell HeaderCell = new TableCell();


rGridRow.Cells.Add(HeaderCell);

         

HeaderCell.Text = "Department";
            HeaderCell.ColumnSpan = 2;
            Head
e  HeaderCell = new TableCell();
            HeaderCell.Text = "Employee";
            HeaderCell.ColumnSpan = 2;


ridRow);

       }


     }

HeaderGridRow.Cells.Add(HeaderCell);

            grvMergeHeader.Controls[0].Controls.AddAt(0, Header

G