DataList 示范

 

虽然 DataList 识别少数特殊命令（如 Select 和 Edit / Update / Cancel），但是在模板内激发的命令字符串可以是任意字符串。对于所有命令都激发 DataList 的 OnItemCommand。如前例所示，可以将该事件与处理程序连接。下面的示例说明如何完成此操作。

MyDataList_ItemCommand     MyDataList_Select    查找模板内的控件  < script runat = " server " >

     protected   void  MyDataList_ItemCommand(Object sender, DataListCommandEventArgs e) {
        String command  =  e.CommandName;

         switch (command) {
           case   " Discussions " :
            ShowDiscussions((DataRowView)e.Item.DataItem);   break ;
           case   " Ratings " :
            ShowRatings((DataRowView)e.Item.DataItem);   break ;
        }
    }

</ script >

< ASP:DataList id = " MyDataList "  OnItemCommand = " MyDataList_ItemCommand "  runat = " server " >

     < ItemTemplate >

         < asp:linkbutton CommandName = " Ratings "  runat = " server " >
            View Ratings
         </ asp:linkbutton >
         |
         < asp:linkbutton CommandName = " Discuss "  runat = " server " >
            View Discussions
         </ asp:linkbutton >

     </ ItemTemplate >

</ ASP:DataList >
// MyDataList_Select 事件处理程序中<%@ Import Namespace="System.Data" %>
<% @ Import Namespace = " System.Data.SqlClient "   %>

< html >
 

< script language = " C# "  runat = " server " >

    SqlConnection myConnection;

     void  Page_Load(Object sender, EventArgs e) {

        myConnection  =   new  SqlConnection( " Server=(local);Integrated Security=SSPI;database=Pubs " );

         if  ( ! Page.IsPostBack) {
            SqlDataAdapter myCommand  =   new  SqlDataAdapter( " select * from Titles where type = 'business' " , myConnection);

            DataSet ds  =   new  DataSet();
            myCommand.Fill(ds,  " 书名 " );

            MyDataList.DataSource = ds.Tables[ " 书名 " ].DefaultView;
            MyDataList.DataBind();
        }

    }

     void  MyDataList_Select(Object sender, EventArgs e) {

        String title  =  MyDataList.DataKeys[MyDataList.SelectedItem.ItemIndex].ToString();
        SqlDataAdapter myCommand  =   new  SqlDataAdapter( " select * from Titles where title_id = ' "   +  title  +   " ' "  , myConnection);

        DataSet ds  =   new  DataSet();
        myCommand.Fill(ds,  " 书名详细信息 " );

        DataRowView rowview  =  ds.Tables[ " 书名详细信息 " ].DefaultView[ 0 ];

        DetailsImage.Src  =   " /quickstart/aspplus/images/title- "   +  rowview[ " title_id " ]  +   " .gif " ;
        DetailsPubId.InnerHtml  =   " <b>出版商 ID：</b> "   +  rowview[ " pub_id " ].ToString()  +   " <br> " ;
        DetailsTitleId.InnerHtml  =   " <b>书名 ID：</b> "   +  rowview[ " title_id " ].ToString()  +   " <br> " ;
        DetailsType.InnerHtml  =   " <b>类别：</b> "   +  rowview[ " type " ].ToString()  +   " <br> " ;
        DetailsPrice.InnerHtml  =   " <b>价格：</b> $  "   +  rowview[ " price " ].ToString()  +   " <p> " ;
        PurchaseLink.InnerHtml  =   " <img border='0' src='/quickstart/aspplus/images/purchase_book.gif' > " ;
        PurchaseLink.HRef = " purchase.aspx?titleid= "   +  rowview[ " title_id " ].ToString();
        DetailsTitle.InnerHtml  =  rowview[ " title " ].ToString();

        DetailsImage.Visible  =   true ;
    }

</ script >

< body topmargin = " 0 "  leftmargin = " 0 "  marginwidth = " 0 "  marginheight = " 0 " >

   < form runat = " server " >

   <!--  #include  virtual = " /quickstart/aspplus/samples/webforms/customize/header.inc "   -->

   < table width = " 100% " >
     < tr >
       < td width = " 50% " >

         < ASP:DataList id = " MyDataList "  OnSelectedIndexChanged = " MyDataList_Select "  DataKeyField = " title_id "  runat = " server " >

           < ItemTemplate >

             < table cellpadding = 10  style = " font: 10.5pt 宋体 " >
               < tr >
                 < td valign = " top " >
                   < img align = " top "  width = " 25 "  border = 1  src = ' <%# DataBinder.Eval(Container.DataItem, "title_id", "/quickstart/aspplus/images/title-{0}.gif") %> '  runat = " server " />
                 </ td >
                 < td valign = " top " >
                   < b > 书名: </ b >
                   < asp:linkbutton Text = ' <%# DataBinder.Eval(Container.DataItem, "title") %> '  CommandName = " select "  style = " color:darkred "  runat = " server " />
                   < br >
                   < b > 价格： </ b ><% # DataBinder.Eval(Container.DataItem,  " price " ,  " $ {0} " )  %>< br >
                 </ td >
               </ tr >
             </ table >

           </ ItemTemplate >

         </ ASP:DataList >

       </ td >

       < td valign = " top "  style = " padding-top:15 "  width = " 50% " >
         < table cellpadding = " 5 "  width = " 100% "  style = " font: 10.5pt 宋体 " >
           < tr >
             < td >
               < img id = " DetailsImage "  visible = " false "  runat = " server " >
             </ td >
             < td valign = " top "  width = " 400 " >
               < div style = " font: 12pt 宋体;color:darkred " >
                 < i >< b >< span id = " DetailsTitle "  runat = " server " /></ i ></ b >< br >
               </ div >
               < span id = " DetailsTitleId "  runat = " server " />
               < span id = " DetailsPubId "  runat = " server " />
               < span id = " DetailsType "  runat = " server " />
               < span id = " DetailsPrice "  runat = " server " />
               < a id = " PurchaseLink "  runat = " server " />
             </ td >
           </ tr >
         </ table >
       </ td >

     </ tr >
   </ table >

   <!--  #include  virtual = " /quickstart/aspplus/samples/webforms/customize/footer.inc "   -->

   </ form >

</ body >
</ html >
        查找模板内的控件 
有时有必要查找模板内包含的控件。如果在模板中给控件赋予了一个 ID，则可以从其容器（父层次结构中支持 INamingContainer 的第一个控件）中检索此控件。本例中，容器是 DataListItem 控件。注意，即使若干控件具有同一 ID（由于 DataList 的重复），每个控件在逻辑上也包含在 DataListItem 容器控件的命名空间中。 

可以在 DataList 的 Items 集合中遍历以检索给定索引的 DataListItem，然后调用 DataListItem 的 FindControl 方法（从基 Control 类继承）检索具有特定 ID 的控件。 

< script runat = " server " >

     public   void  Page_Load(Object sender, EventArgs E)) {
         //  set datasource and call databind here

         for  ( int  i = 0 ; i < MyDataList.Items.Count; i ++ ) {
           String isChecked  =  ((CheckBox) MyDataList.Items[i].FindControl( " Save " )).Checked.ToString();
           If (isChecked  ==   " True " ) {
             
           }
        }
    }
</ script >

< ASP:DataList id = " MyDataList "  runat = " server " >

     < ItemTemplate >
          < asp:CheckBox id = " Save "  runat = " server " />   < b > Save to Favorites </ b >
     </ ItemTemplate >

</ ASP:DataList >
< script runat = " server " >

    Public Sub Page_Load(sender As Object, E As EventArgs))
         '  set datasource and call databind here

        For I = 0  To MyDataList.Items.Count - 1
           Dim IsChecked As String  =   MyDataList.Items(i).FindControl( " Save " ).Checked.ToString()
           If IsChecked  =   " True "  Then
             
           End If
        Next
    End Sub
</ script >

< ASP:DataList id = " MyDataList "  runat = " server " >

     < ItemTemplate >
          < asp:CheckBox id = " Save "  runat = " server " />   < b > Save to Favorites </ b >
     </ ItemTemplate >

</ ASP:DataList >
< script runat = " server " >

     public  function Page_Load(sender:Object, E:EventArgs)) :  void  {
         //  set datasource and call databind here

         for  (var i: int = 0 ; i < MyDataList.Items.Count; i ++ ) {
           var isChecked:String  =  (CheckBox(MyDataList.Items[i].FindControl( " Save " ))).Checked.ToString();
           If (isChecked  ==   " True " ) {
             
           }
        }
    }
</ script >

< ASP:DataList id = " MyDataList "  runat = " server " >

     < ItemTemplate >
          < asp:CheckBox id = " Save "  runat = " server " />   < b > Save to Favorites </ b >
     </ ItemTemplate >

</ ASP:DataList >