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DataList.SelectedItem Eigenschaft

Definition

Ruft das im DataList-Steuerelement ausgewählte Element ab.

public:
 virtual property System::Web::UI::WebControls::DataListItem ^ SelectedItem { System::Web::UI::WebControls::DataListItem ^ get(); };
[System.ComponentModel.Browsable(false)]
public virtual System.Web.UI.WebControls.DataListItem SelectedItem { get; }
[<System.ComponentModel.Browsable(false)>]
member this.SelectedItem : System.Web.UI.WebControls.DataListItem
Public Overridable ReadOnly Property SelectedItem As DataListItem

Eigenschaftswert

Ein DataListItem, das das im DataList-Steuerelement ausgewählte Element darstellt.

Attribute

Beispiele

Im folgenden Codebeispiel wird veranschaulicht, wie die SelectedItem -Eigenschaft verwendet wird, um den Inhalt des ausgewählten Elements im DataList Steuerelement anzuzeigen.

Hinweis

Das folgende Codebeispiel verwendet das Einzeldateicodemodell und funktioniert möglicherweise nicht ordnungsgemäß, wenn es direkt in eine CodeBehind-Datei kopiert wird. Dieses Codebeispiel muss in eine leere Textdatei mit einer .aspx-Erweiterung kopiert werden. Weitere Informationen zum Web Forms-Codemodell finden Sie unter ASP.NET Web Forms-Seitencodemodell.

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!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>
    <title>DataList SelectedItem Example</title>
<script language="C#" runat="server">

      public DataTable Cart;
      public DataView CartView;

      void Page_Load(Object sender, EventArgs e) 
      {
         if (Session["DL3_ShoppingCart"] == null) 
         {
            Cart = new DataTable();
            Cart.Columns.Add(new DataColumn("Qty", typeof(string)));
            Cart.Columns.Add(new DataColumn("Item", typeof(string)));
            Cart.Columns.Add(new DataColumn("Price", typeof(string)));
            Session["DL3_ShoppingCart"] = Cart;

            // First Load - Create some data.
            for (int i=1; i<=9; i++) 
            {
               DataRow dr = Cart.NewRow();
               dr[0] = ((i%2)+1).ToString();
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i+1)).ToString();
               Cart.Rows.Add(dr);
            }
         }
         else
            Cart = (DataTable)Session["DL3_ShoppingCart"];

         CartView = new DataView(Cart);
         CartView.Sort = "Item";
         if (!IsPostBack)
            BindList();
      }

      void BindList() 
      {
         DataList1.DataSource= CartView;
         DataList1.DataBind();
      }

      void DataList_ItemCommand(Object sender, DataListCommandEventArgs e) 
      {
         DataList1.SelectedIndex = e.Item.ItemIndex;
         BindList();
         Label4.Text = "You selected: "  + 
                       ((Label)DataList1.SelectedItem.FindControl("Label1")).Text;
      }

      void Button_Click(Object sender, EventArgs e)
      { 
         if (DataList1.SelectedItem != null)
         {
            DataList1.SelectedItem.ForeColor = System.Drawing.Color.Red;
         }
      }

   </script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList SelectedItem Example</h3>
      <p></p>
       
      <asp:DataList id="DataList1" runat="server"
           GridLines="Both"
           CellPadding="3"
           CellSpacing="0"           
           OnItemCommand="DataList_ItemCommand">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <SelectedItemStyle BackColor="lightgreen">
         </SelectedItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            <asp:LinkButton id="button1" 
                 Text="Select" 
                 CommandName="select"
                 runat="server"/>
            <%# ((DataRowView)Container.DataItem)["Item"]  %>

         </ItemTemplate>
              
         <SelectedItemTemplate>

            Item:
            <asp:Label id="Label1" 
                 Text='<%# ((DataRowView)Container.DataItem)["Item"] %>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:Label id="Label2" 
                 Text='<%# ((DataRowView)Container.DataItem)["Qty"] %>' 
                 runat="server"/>

            <br />

            Price:
            <asp:Label id="Label3" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price") %>' 
                 runat="server"/>

         </SelectedItemTemplate>

      </asp:DataList>

      <br /><br />

      <asp:Label id="Label4"
           runat="server"/>

      <br /><br />

      <asp:Button id="Button2"
           Text="Change Text to Red" 
           OnClick="Button_Click"
           runat="server"/>

   </form>

</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>

<!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>
    <title>DataList SelectedItem Example</title>
<script language="VB" runat="server">
 
    Dim Cart As DataTable
    Dim CartView As DataView

    Sub Page_Load(sender As Object, e As EventArgs)
        If Session("DL3_ShoppingCart") Is Nothing Then
            Cart = New DataTable()
            Cart.Columns.Add(New DataColumn("Qty", GetType(String)))
            Cart.Columns.Add(New DataColumn("Item", GetType(String)))
            Cart.Columns.Add(New DataColumn("Price", GetType(String)))
            Session("DL3_ShoppingCart") = Cart
            
            ' First Load - Create some data.
            Dim i As Integer
            For i = 1 To 9
                Dim dr As DataRow = Cart.NewRow()
                dr(0) =(i Mod 2 + 1).ToString()
                dr(1) = "Item " & i.ToString()
                dr(2) =(1.23 *(i + 1)).ToString()
                Cart.Rows.Add(dr)
            Next i
        Else
            Cart = CType(Session("DL3_ShoppingCart"), DataTable)
        End If 
        CartView = New DataView(Cart)
        CartView.Sort = "Item"
        If Not IsPostBack Then
            BindList()
        End If
    End Sub 'Page_Load
     
    Sub BindList()
        DataList1.DataSource = CartView
        DataList1.DataBind()
    End Sub 'BindList

    Sub DataList_ItemCommand(sender As Object, e As DataListCommandEventArgs)
        DataList1.SelectedIndex = e.Item.ItemIndex
        BindList()
        Label4.Text = "You selected: " & CType(DataList1.SelectedItem.FindControl("Label1"), Label).Text
    End Sub 'DataList_ItemCommand

    Sub Button_Click(sender As Object, e As EventArgs)
        If Not (DataList1.SelectedItem Is Nothing) Then
            DataList1.SelectedItem.ForeColor = System.Drawing.Color.Red
        End If
    End Sub 'Button_Click

</script>

</head>
<body>

   <form id="form1" runat="server">

      <h3>DataList SelectedItem Example</h3>
      <p></p>
       
      <asp:DataList id="DataList1" runat="server"
           GridLines="Both"
           CellPadding="3"
           CellSpacing="0"           
           OnItemCommand="DataList_ItemCommand">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <SelectedItemStyle BackColor="lightgreen">
         </SelectedItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
         
         <ItemTemplate>

            <asp:LinkButton id="button1" 
                 Text="Select" 
                 CommandName="select"
                 runat="server"/>
            <%# (CType(Container.DataItem, DataRowView))("Item")%>

         </ItemTemplate>
              
         <SelectedItemTemplate>

            Item:
            <asp:Label id="Label1" 
                 Text='<%# (CType(Container.DataItem, DataRowView))("Item")%>' 
                 runat="server"/>

            <br />

            Quantity:
            <asp:Label id="Label2" 
                 Text='<%# (CType(Container.DataItem, DataRowView))("Qty")%>' 
                 runat="server"/>

            <br />

            Price:
            <asp:Label id="Label3" 
                 Text='<%# DataBinder.Eval(Container.DataItem, "Price")%>' 
                 runat="server"/>

         </SelectedItemTemplate>

      </asp:DataList>

      <br /><br />

      <asp:Label id="Label4"
           runat="server"/>

      <br /><br />

      <asp:Button id="Button2"
           Text="Change Text to Red" 
           OnClick="Button_Click"
           runat="server"/>

   </form>

</body>
</html>

Hinweise

Verwenden Sie die SelectedItem -Eigenschaft, um ein DataListItem -Objekt abzurufen, das das ausgewählte Element im DataList Steuerelement darstellt. Dieses Objekt kann dann verwendet werden, um auf die Eigenschaften des ausgewählten Elements zuzugreifen.

Gilt für:

Weitere Informationen