<asp:GridView ID="gvItem" Width="600px" OnRowDataBound="gvItem_RowCommand" DataKeyNames="ID"

                    runat="server" AutoGenerateColumns="False">

                    <Columns> 

                        <asp:TemplateField>

                            <ItemStyle Width="1%" />

                            <ItemTemplate>

                                <%-- 

                              <span id='btnShowHidden<%#Eval("id") %>' style="float: right; color: Red; cursor: pointer;

                                    margin: 0 0 0 0" onclick="ShowHidden('<%#Eval("id") %>',event)">展开列表</span> --%>

                              <img id='img<%#Eval("id")%>' style="border: 0px; padding-left: 20px;" src="Image/maximize.gif" onclick="ShowHidden('<%#Eval("id") %>',event)" />

                            </ItemTemplate>

                        </asp:TemplateField>