asp.net 2.0技巧3

  今天看台湾章立民的书<<asp.net ajax 168范例》了，看到了讲updatepannel中如何设定
childrenastriggers的问题，当childrenastriggers设置为falase时，是很有用的（默认是true),
比如一个购物车，左边是商品的列表，用一个updatepannel里包住一个datalist,当点
datalist的书名时，在右边的一个updatepannel里的datalist里，显示这商品的具体信息。
关键部分如下：
   左边部分
 <asp:UpdatePanel ID="UpdatePanel1" runat="server" ChildrenAsTriggers="False" UpdateMode="Conditional">
                        <ContentTemplate>
                            <asp:DataList ID="MyDataList" DataKeyField="书号" runat="server" Width="248px" DataSourceID="SqlDataSourceChtNorthwind">
                                <ItemTemplate>
                                    <table cellpadding="10" style="font: 10pt verdana">
                                        <tr>
                                            <td valign="top">
                                                <img id="Img1" alt="book image" align="top" border="1" src='<%# Eval("书号", "DisplayBookImage.ashx?Title_Id={0}") %>'
                                                    runat="server" style="width: 96px; height: 128px" />
                                            </td>
                                            <td valign="top" style="width: 339px">
                                                <b>书名：<br />
                                                </b>
                                                <asp:LinkButton ID="Linkbutton1" Text='<%# Eval("书名") %>' CommandName="Select" runat="server"
                                                    Width="184px" />
                                                <br>
                                                <b>价格：</b><asp:Label ID="lblPrice" runat="server" Text='<%# Eval("价格", "{0:n0}") %>' /><br>
                                                <div>
                                                    <asp:CheckBox ID="AddBag" runat="server" Text="加入购物袋" /><img src="Images/ShoppingBag.gif"
                                                        style="vertical-align: middle" />
                                                </div>
                                            </td>
                                        </tr>
                                    </table>
                                </ItemTemplate>
                            </asp:DataList><asp:SqlDataSource ID="SqlDataSourceChtNorthwind" runat="server" ConnectionString="<%$ ConnectionStrings:chtNorthwind %>"
                                SelectCommand="SELECT * FROM [章立民研究室图书]"></asp:SqlDataSource>
                        </ContentTemplate>
                    </asp:UpdatePanel>

右边部分
 <asp:UpdatePanel ID="UpdatePanel2" runat="server" UpdateMode="Conditional">
                        <ContentTemplate>
                            <table cellpadding="5" width="100%" style="font: 10pt verdana">
                                <tr>
                                    <td style="width: 312px; height: 461px;">
                                        <asp:DataList ID="DataList1" runat="server" DataSourceID="SqlDataSourceTargetBook"
                                            DataKeyField="书号" Width="544px">
                                            <ItemTemplate>
                                                <table border="1" style="width: 576px">
                                                    <tr>
                                                        <td colspan="2" rowspan="1" style="background-color: #ffff99" valign="top">
                                                            <font color="#800000" size="3"><i><b>
                                                                <%#Eval("书名")%>
                                                            </b></i></font>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td rowspan="7" style="width: 215px; background-color: #ffff99" valign="top">
                                                            <img src='<%# Eval("书号", "DisplayBookLargeImage.ashx?Title_Id={0}") %>' style="width: 336px;
                                                                height: 453px" /></td>
                                                        <td style="width: 14865899px; background-color: #ffff99;" valign="top">
                                                            <b>书号：</b><%#Eval("书号")%>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td style="width: 14865899px; background-color: #ffff99;" valign="top">
                                                            <b>ISBN：</b><%#Eval("ISBN")%>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td style="width: 14865899px; background-color: #ffff99" valign="top">
                                                            <b>类：</b><%#Eval("类别")%>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td style="width: 14865899px; background-color: #ffff99" valign="top">
                                                            <b>价格：</b><%#Eval("价格", "{0:c}")%>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td style="width: 14865899px; background-color: #ffff99" valign="top">
                                                            <b>作者：</b><%#Eval("作者")%>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td style="width: 14865899px; background-color: #ffff99; height: 267px;" valign="top">
                                                            <b>内容特色：</b><br />
                                                            <%#Eval("内容特色")%>
                                                        </td>
                                                    </tr>
                                                    <tr>
                                                        <td style="width: 14865899px; background-color: #ffff99; height: 29px;" valign="top">
                                                            <a target="_blank" href="http://liminzhang.cnblogs.com/">
                                                                <img border="0" src="images/Noodle.jpg" title="前往立民讲堂"></a></td>
                                                    </tr>
                                                </table>
                                            </ItemTemplate>
                                        </asp:DataList>
                                        <asp:SqlDataSource ID="SqlDataSourceTargetBook" runat="server" ConnectionString="<%$ ConnectionStrings:chtNorthwind %>"
                                            SelectCommand="SELECT * FROM dbo.章立民研究室图书 WHERE (书号 = @Title_Id)" DataSourceMode="DataReader">
                                            <SelectParameters>
                                                <asp:ControlParameter ControlID="MyDataList" Name="Title_Id" PropertyName="SelectedValue"
                                                    Size="9" Type="String" />
                                            </SelectParameters>
                                        </asp:SqlDataSource>
                                    </td>
                                </tr>
                            </table>
                        </ContentTemplate>
                        <Triggers>
                            <asp:AsyncPostBackTrigger ControlID="MyDataList" EventName="SelectedIndexChanged" />
                        </Triggers>
                    </asp:UpdatePanel>