<asp:TemplateColumn HeaderText="temp">
<ItemTemplate>
<asp:ImageButton id="ImageButton1" runat="server"
	ImageUrl='<%# DataBinder.Eval(Container,"DataItem.ImgUrl")%>'
	CommandName="ImageClick" CommandArgument='<%# DataBinder.Eval(Container,"DataItem.id")%>'>
</asp:ImageButton>
</ItemTemplate>
</asp:TemplateColumn>

DataGrid1.ItemCommand += new DataGridCommandEventHandler(DataGrid1_ItemCommand);

//....

private void DataGrid1_ItemCommand(object source, DataGridCommandEventArgs e)
{
	Response.Write(string.Format("{0}<br>{1}",e.CommandArgument,e.CommandName));
}