ASP.NET笔记之 ListView 与 DropDownList的使用

1、repeater用来显示数据、listview用来操作数据

insertitemtemplate和updateitemtemplate
**eval（显示数据）和bind（双向绑定：不仅是需要展现，更需要把数据绑定到数据库中）

itemplaceholderid：占位符，决定占位，把头部（之上）和尾部（之下）分隔开
itemtemplate：展示功能

自动生成的listview需要调整的地方
（1、生成的样式要提到style中，不要用内联的方式
（2、itemtemplate里面一半没必要用<asp:label>展示只读数据，所以可以直接输出
<%#eval("id")%>
(3、layouttemplate中必须有一个itempplaceholderid 的服务端控件
(4、layouttemplate中表头的位置要汉化，所有template中的不需显示的字段需删除或更改位置

2、事件
流程同repeater：

//首先判断数据行的类型
e.item.itemtype==listviewitemtype.dataitem

//把e.item转化成listviewdataitem才能拿到dataitem
listviewdataitem lvdataitem=(listviewdataitem)e.item;
datarowview rowview=(datarowview)lvdataitem.dataitem;
//获得某一列
var xrow=(...dal.dataset1.t_userrow)rowview.row;
//获得某一列的值
xrow.age、xrow.sname...etc.

3、具体注意
（1、设定相应的按钮、控件、validator为童颜的validationgroup，
防止不同模板中的validator互相干扰，
（2、将cancel按钮中的causesvalidation="false"使得插入修改数据时
可以取消操作，这样即使在同一个分组内也可以不互相影响

4、给insertitemplate增加默认值
//在itemcreate属性中进入函数
if(e.item.itemtype==listviewitemtype.insertitem){
textbox agetext=（textbox)e.item.findcontrol("ageid");
agetext.text="20";
}

5、主键guid：插入到数据库

（1、listview的iteminserting属性：
//要插入到数据库之前的数据的键值对
e.values["id"]=guid.newguid();

（2、listview的itemupdateing属性：
e.itemidex
e.oldvalues//更新前的值
e.newvalues["age"]//更新后的值
e.cancel=true;//取消非法数据插入

objectdatasource
绑定id为guid 类型的时候

 6、dropdrownlist

（1、
//包含在dropdrownlist中的项
<asp:listitem value="man">男</asp:listitem>

（2、
**后台代码：更新的时候
//找到listview
//listview1.item[e.itemindex].findcontrol("id");
//它是一个dropviewlist
dropdrownlist d=(dropdrownlist)listview1.item[e.itemindex].findcontrol("id");
//赋值
e.newvalues=["字段"]=d.selectedvalue;

（3、
**后台代码：实现编辑时显示原先的数据
//有数据行
if(e.item.itemtype==listviewdatalist.dataitem){
//取控件
dropdownlist d=(dropdownlist)e.item.findcontrol("id");

if(d!=null){
//取到这一行绑定的数据
listviewdataitem lv=(listviewdataitem)e.item;
datarowitem row=(datarowitem)lv.dataitem;
//如果这一行有数据
if(row!=null){
//读取数据库该row的值
var myrow=(项目名称.dal.datasetusers.t_users)row.row;

//将读取打偶的row值设置为下拉菜单中的选项
d.selectedvalue=myrow.字段;
}
}
}

（4、 可以看不可以用 enabled="false

 

友情链接管理：

效果：

存在问题总结：

（1、警告 1 元素“listview”不是已知元素。原因可能是网站中存在编译错误，或者缺少 web.config 文件。 e:\code\projects\website_zzl01\友情链接\linkurl_admin.aspx 39 10 友情链接

（2、onlinktypechange(this,'" + logoid.clientid + "') 中传给前台javascript的id不是客户端的id，会导致显示和隐藏的功能无法实现，所以增加一个myid

：   logoid.attributes["myid"] = logoid.clientid; 来传递参数

linkurl_admin.aspx.cs

using system;
 using system.collections.generic;
 using system.linq;
 using system.web;
 using system.web.ui;
 using system.web.ui.webcontrols;
 using system.data;

 namespace 友情链接
 {
     public partial class linkurl_admin : system.web.ui.page
     {
         protected void page_load(object sender, eventargs e)
         {

         }

         protected void listview1_itemdatabound(object sender, listviewitemeventargs e)
         {
             //listview1的属性itemdatabound数据绑定每一行
             //显示数据
             if (e.item.itemtype == listviewitemtype.dataitem) {
                 dropdownlist ddlslinktype = (dropdownlist)e.item.findcontrol("ddlslinktype");
                 listviewdataitem dataitem = (listviewdataitem)e.item;
                 datarowview myrow = (datarowview)dataitem.dataitem;

                 if (ddlslinktype != null && myrow != null) {
                     var surl = (友情链接.adl.dataset1.t_linksrow)myrow.row;
                     ddlslinktype.selectedvalue = surl.slinktype;
                 }
             }

         }

         protected void listview1_iteminserting(object sender, listviewinserteventargs e)
         {
             //插入数据
             dropdownlist ddlslinktype = (dropdownlist)e.item.findcontrol("ddlslinktype");
             e.values["slinktype"] = ddlslinktype.selectedvalue;   
         }

         protected void listview1_itemupdating(object sender, listviewupdateeventargs e)
         {
             //更新数据
             dropdownlist ddlslinktype = (dropdownlist)listview1.items[e.itemindex].findcontrol("ddlslinktype");
             e.newvalues["slinktype"] = ddlslinktype.selectedvalue;
         }

         protected void listview1_itemcreated(object sender, listviewitemeventargs e)
         {
             if (e.item.itemtype == listviewitemtype.dataitem || e.item.itemtype ==
                 listviewitemtype.insertitem) {
                dropdownlist ddlslinktype = (dropdownlist)e.item.findcontrol("ddlslinktype");
                textbox logoid = (textbox)e.item.findcontrol("logourltextbox");
                 if (ddlslinktype != null&&logoid!=null) {
                     //onchange是html中select的属性
                     //onlinktypechange是后台代码调用前台javascript中自定义的jquery函数

                     logoid.attributes["myid"] = logoid.clientid;

                     ddlslinktype.attributes["onchange"] = "onlinktypechange(this,'" + logoid.clientid + "')";
                     if(ddlslinktype.selectedvalue=="text"){
                         logoid.style["display"] = "none";
                     }
                 }
             }
         }
     }
 }

linkurl_admin.aspx

<%@ page language="c#" autoeventwireup="true" codebehind="linkurl_admin.aspx.cs" inherits="友情链接.linkurl_admin" %>

 <!doctype html public "-//w3c//dtd xhtml 1.0 transitional//en" "http://www.w3.org/tr/xhtml1/dtd/xhtml1-transitional.dtd">

 <html xmlns="http://www.w3.org/1999/xhtml">
 <head runat="server">
     <title>友情链接管理页面</title>
     <script src="scripts/jquery-1.4.2.js" type="text/javascript"></script>
     <script type="text/javascript">
         function onlinktypechange(urltype, logoid) {
             if ($(urltype).val() == "text") {
                 $("input:text[myid=" + logoid + "]").hide();
                 //$("#" + logoid).hide(); //传到到客户端不是客户端的id
                 //$("#listview1_logourltextbox").hide();//真正的id
             }
             else {
                 $("input:text[myid=" + logoid + "]").show();
                 //$("#" + logoid).show();
             }
         }
     </script>
 </head>
 <body>
     <form id="form1" runat="server">
     <div>

         <asp:objectdatasource id="objectdatasource1" runat="server"
             deletemethod="delete" insertmethod="insert"
             oldvaluesparameterformatstring="original_{0}" selectmethod="getdata"
             typename="友情链接.adl.dataset1tableadapters.t_linkstableadapter"
             updatemethod="update">
             <deleteparameters>
                 <asp:parameter name="original_id" type="int64" />
             </deleteparameters>
             <insertparameters>
                 <asp:parameter name="seono" type="int32" />
                 <asp:parameter name="sitename" type="string" />
                 <asp:parameter name="slinktype" type="string" />
                 <asp:parameter name="siteurl" type="string" />
                 <asp:parameter name="logourl" type="string" />
             </insertparameters>
             <updateparameters>
                 <asp:parameter name="seono" type="int32" />
                 <asp:parameter name="sitename" type="string" />
                 <asp:parameter name="slinktype" type="string" />
                 <asp:parameter name="siteurl" type="string" />
                 <asp:parameter name="logourl" type="string" />
                 <asp:parameter name="original_id" type="int64" />
             </updateparameters>
         </asp:objectdatasource>

     </div>
     <asp:listview id="listview1" runat="server" datakeynames="id"
         datasourceid="objectdatasource1" insertitemposition="lastitem"
         onitemdatabound="listview1_itemdatabound"
         oniteminserting="listview1_iteminserting"
         onitemupdating="listview1_itemupdating"
         onitemcreated="listview1_itemcreated">

         <edititemtemplate>
             <tr style="background-color: #999999;">
                 <td>
                     <asp:button id="updatebutton" runat="server" commandname="update" text="更新" />
                     <asp:button id="cancelbutton" runat="server" commandname="cancel" text="取消" />
                 </td>
                 <td>
                     <asp:textbox id="seonotextbox" runat="server" text='<%# bind("seono") %>' />
                 </td>
                 <td>
                     <asp:textbox id="sitenametextbox" runat="server"
                         text='<%# bind("sitename") %>' />
                 </td>
                 <td>
                    <asp:dropdownlist id="ddlslinktype" runat="server">
                      <asp:listitem value="text">文本</asp:listitem>
                      <asp:listitem value="pic">图片</asp:listitem>
                    </asp:dropdownlist>
                 </td>
                 <td>
                     <asp:textbox id="siteurltextbox" runat="server" text='<%# bind("siteurl") %>' />
                 </td>
                 <td>
                     <asp:textbox id="logourltextbox" runat="server" text='<%# bind("logourl") %>' />
                 </td>
             </tr>
         </edititemtemplate>
         <emptydatatemplate>
             <table runat="server"
                 style="background-color: #ffffff;border-collapse: collapse;border-color: #999999;border-style:none;border-width:1px;">
                 <tr>
                     <td>
                         未返回数据。</td>
                 </tr>
             </table>
         </emptydatatemplate>
         <insertitemtemplate>
             <tr style="">
                 <td>
                     <asp:button id="insertbutton" runat="server" commandname="insert" text="插入" validationgroup="insert" />
                     <asp:button id="cancelbutton" runat="server" commandname="cancel" text="清除" />
                 </td>
                 <td>
                     <asp:textbox id="seonotextbox" validationgroup="insert" runat="server" text='<%# bind("seono") %>' />
                     <asp:requiredfieldvalidator validationgroup="insert" id="requiredfieldvalidator1" runat="server" errormessage="*" controltovalidate="seonotextbox">
                     </asp:requiredfieldvalidator>
                     <asp:comparevalidator validationgroup="insert" id="comparevalidator1" runat="server" errormessage="序号必须为整数" controltovalidate="seonotextbox" operator="datatypecheck" type="integer">
                     </asp:comparevalidator>
                 </td>
                 <td>
                     <asp:textbox id="sitenametextbox" validationgroup="insert" runat="server" maxlength="50"
                         text='<%# bind("sitename") %>' />
                     <asp:requiredfieldvalidator validationgroup="insert" id="requiredfieldvalidator2" runat="server" errormessage="*" controltovalidate="sitenametextbox">
                     </asp:requiredfieldvalidator>
                 </td>
                 <td>
                    <asp:dropdownlist id="ddlslinktype" validationgroup="insert" runat="server" >
                      <asp:listitem value="text">文本</asp:listitem>
                      <asp:listitem value="pic">图片</asp:listitem>
                    </asp:dropdownlist>
                 </td>
                 <td>
                     <asp:textbox id="siteurltextbox" validationgroup="insert" runat="server" text='<%# bind("siteurl") %>' />
                     <asp:requiredfieldvalidator validationgroup="insert" id="requiredfieldvalidator3" runat="server" errormessage="*" controltovalidate="siteurltextbox">
                     </asp:requiredfieldvalidator>
                 </td>
                 <td>
                     <asp:textbox id="logourltextbox" validationgroup="insert" runat="server" text='<%# bind("logourl") %>' />
                 </td>
             </tr>
         </insertitemtemplate>
         <itemtemplate>
             <tr style="background-color: #e0ffff;color: #333333;">
                 <td>
                     <asp:button id="deletebutton" runat="server" commandname="delete" text="删除" />
                     <asp:button id="editbutton" runat="server" commandname="edit" text="编辑" />
                 </td>
                 <td>
                     <asp:label id="seonolabel" runat="server" text='<%# eval("seono") %>' />
                 </td>
                 <td>
                     <asp:label id="sitenamelabel" runat="server" text='<%# eval("sitename") %>' />
                 </td>
                 <td>
                    <asp:dropdownlist id="ddlslinktype" runat="server" enabled="false">
                      <asp:listitem value="text">文本</asp:listitem>
                      <asp:listitem value="pic">图片</asp:listitem>
                    </asp:dropdownlist>
                 </td>
                 <td>
                     <asp:label id="siteurllabel" runat="server" text='<%# eval("siteurl") %>' />
                 </td>
                 <td>
                     <asp:label id="logourllabel" runat="server" text='<%# eval("logourl") %>' />
                 </td>
             </tr>
         </itemtemplate>
         <layouttemplate>
             <table runat="server">
                 <tr runat="server">
                     <td runat="server">
                         <table id="itemplaceholdercontainer" runat="server" border="1"
                             style="background-color: #ffffff;border-collapse: collapse;border-color: #999999;border-style:none;border-width:1px;font-family: verdana, arial, helvetica, sans-serif;">
                             <tr runat="server" style="background-color: #e0ffff;color: #333333;">
                                 <th runat="server">
                                 </th>
                                 <th runat="server">
                                     序号</th>
                                 <th runat="server">
                                     网站名称</th>
                                 <th runat="server">
                                     链接类型</th>
                                 <th runat="server">
                                     网站网址</th>
                                 <th runat="server">
                                     logo网址</th>
                             </tr>
                             <tr id="itemplaceholder" runat="server">
                             </tr>
                         </table>
                     </td>
                 </tr>
                 <tr runat="server">
                     <td runat="server"
                         style="text-align: center;background-color: #5d7b9d;font-family: verdana, arial, helvetica, sans-serif;color: #ffffff">
                         <asp:datapager id="datapager1" runat="server">
                             <fields>
                                 <asp:nextpreviouspagerfield buttontype="button" showfirstpagebutton="true"
                                     showlastpagebutton="true" />
                             </fields>
                         </asp:datapager>
                     </td>
                 </tr>
             </table>
         </layouttemplate>
     </asp:listview>
     </form>
 </body>
 </html>