You can do that in aspx file.
<asp:GridView ID="searchProductGridView" runat="server" AutoGenerateColumns="false" DataKeyNames="ProductCode"
CssClass="gridview" AlternatingRowStyle-CssClass="alternatingRow" AllowPaging="true" PagerStyle-CssClass="paging" OnPageIndexChanging="searchProductGridView_PageIndexChanging">
<Columns>
<asp:TemplateField HeaderText="Select">
<ItemTemplate>
<asp:CheckBox ID="selectChkBox" runat="server" ToolTip="Add to Cart" />
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Code" ControlStyle-Width="150px">
<ItemTemplate>
<asp:LinkButton ID="codeLink" runat="server" Font-Size="9" ForeColor="#1C329F" CssClass="link" Font-Underline="false"
Text='<%#Eval("ProductCode") %>' OnClick="codeLink_Click" />
</ItemTemplate>
</asp:TemplateField>
and .aspx.cs file :