How to find gridview RowIndex in C#.Net?

In client side(Default.aspx)

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" DataKeyNames="Id" OnRowCommand="GridView1_RowCommand" BorderWidth="1px" CellPadding="3" CellSpacing="2">

                <Columns>

                    <asp:TemplateField>

                        <ItemTemplate>

                            <asp:LinkButton ID="lnkEdit" runat="server" CommandArgument='<%# Eval("Id") %>' CommandName="lnkEdit" Text="Edit" ForeColor="#BC4510" />

                        </ItemTemplate>

                    </asp:TemplateField>

                </Columns>
 </asp:GridView> 

In Code behind(Default.aspx.cs)

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)

{
  if (e.CommandName == "lnkEdit")

   {
    int RowIndex = ((GridViewRow)((LinkButton)e.CommandSource).NamingContainer).RowIndex;
   }
}