here is code for delete button.
in aspx file we add code:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" CellPadding="4" EnableModelValidation="True"
Font-Names="Tahoma" Font-Size="8pt" ForeColor="#333333" Width="100%" OnRowCommand="GridView1_RowCommand">
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
<Columns>
<asp:BoundField DataField="No" HeaderText="No.">
<HeaderStyle Width="100px" />
<ItemStyle Width="100px" />
</asp:BoundField>
<asp:TemplateField HeaderText="Delete">
<HeaderStyle Width="50px" />
<ItemStyle Width="50px" />
<ItemTemplate>
<asp:ImageButton runat="server" CommandName="delete" ImageUrl="~/images/delete.png" CommandArgument='<%#Eval("ID")%>' />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="CustName" HeaderText="Name" />
</Columns>
<EditRowStyle BackColor="#999999" />
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
</asp:GridView>
And in code behind we add following code:
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName.Equals("delete", StringComparison.OrdinalIgnoreCase))
{
var rowId = Convert.ToInt32(e.CommandArgument);
GridView1.DataBind();
}
}