You can Bind the command argument with the LinkButton and pass into RowCommand Event. Let say you have below Template Field.
<asp:templatefield xmlns:asp="#unknown">
<headertemplate>
Status
</headertemplate>
<itemtemplate>
<asp:imagebutton commandname="DataCommand" commandargument="<%# Eval("ID" )%>" text="<%# Eval("WebSite" )%>" imageurl="/test.pmg">
ID="lnk" runat="server" />
</asp:imagebutton></itemtemplate>
</asp:templatefield>
And here is the code you need to write in order to get the image button click,
Protected Void Grid_RowCommand(object sender, GridViewEventArgs e)
{
if(e.CommandName=="DataCommand")
{
var value= e.CommandArgument;
}
}
Hope this will help.