这应该可以.
我在这里找到的:http://forums.asp.net/p/1331581/2678206.aspx
<asp:TemplateField ShowHeader="False">
<ItemTemplate>
<asp:ImageButton ID="DeleteButton" runat="server" ImageUrl="~/site/img/icons/cross.png"
CommandName="Delete" OnClientClick="return confirm('Are you sure you want to delete this event?');"
AlternateText="Delete" />
</ItemTemplate>
</asp:TemplateField>