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ListControl.SelectedIndexChanged 事件

定義

當清單控制項的選取項目在發佈至伺服器期間變更時發生。

public:
 event EventHandler ^ SelectedIndexChanged;
public event EventHandler SelectedIndexChanged;
member this.SelectedIndexChanged : EventHandler 
Public Custom Event SelectedIndexChanged As EventHandler 

事件類型

範例

下列範例示範如何指定 和 撰寫事件處理常式 SelectedIndexChanged 的程式碼,以顯示使用者所做的選取範圍。

<%@ 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" >
 <script language="c#" runat="server">
 
    ICollection CreateDataSource() {
       DataTable dt = new DataTable();
       DataRow dr;
 
       dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
       dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
       dt.Columns.Add(new DataColumn("DateTimeValue", typeof(DateTime)));
       dt.Columns.Add(new DataColumn("BoolValue", typeof(bool)));
       dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
 
       for (int i = 0; i < 9; i++) {
          dr = dt.NewRow();
 
          dr[0] = i;
          dr[1] = "Item " + i.ToString();
          dr[2] = DateTime.Now;
          dr[3] = (i % 2 != 0) ? true : false;
          dr[4] = 1.23 * (i+1);
 
          dt.Rows.Add(dr);
       }
 
       DataView dv = new DataView(dt);
       return dv;
    }
 
    void Page_Load(Object sender, EventArgs e) {
       if (!IsPostBack) {
          RadioButtonList1.DataSource = CreateDataSource();
          RadioButtonList1.DataTextField="StringValue";
          RadioButtonList1.DataValueField="CurrencyValue";
          RadioButtonList1.DataBind();
       }
    }
 
    void Index_Changed(Object sender, EventArgs e) {
 
       Label1.Text = "You selected " + RadioButtonList1.SelectedItem.Text +
                     " with a value of $" + RadioButtonList1.SelectedItem.Value +
                     ".";
 
    }
 
 </script>
 
 <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
 
    <form id="form1" runat="server">
 
       <asp:RadioButtonList id="RadioButtonList1" 
            OnSelectedIndexChanged="Index_Changed"
            AutoPostBack="true"
            runat="server"/>
 
       <br />
 
       <asp:Label id="Label1" 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" >
 <script language="vb" runat="server">

    Function CreateDataSource() As ICollection
        Dim dt As New DataTable()
        Dim dr As DataRow
        
        dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
        dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
        dt.Columns.Add(New DataColumn("DateTimeValue", GetType(DateTime)))
        dt.Columns.Add(New DataColumn("BoolValue", GetType(Boolean)))
        dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
        
        Dim i As Integer
        For i = 0 To 8
            dr = dt.NewRow()
            
            dr(0) = i
            dr(1) = "Item " + i.ToString()
            dr(2) = DateTime.Now
            If (i Mod 2) <> 0 Then
                dr(3) = True
            Else
                dr(3) = False
            End If
            dr(4) = 1.23 *(i + 1)
            
            dt.Rows.Add(dr)
        Next i
        
        Dim dv As New DataView(dt)
        Return dv
    End Function

    Sub Page_Load(sender As Object, e As EventArgs)
        If Not IsPostBack Then
            RadioButtonList1.DataSource = CreateDataSource()
            RadioButtonList1.DataTextField = "StringValue"
            RadioButtonList1.DataValueField = "CurrencyValue"
            RadioButtonList1.DataBind()
        End If
    End Sub

    Sub Index_Changed(sender As Object, e As EventArgs)        
        Label1.Text = "You selected " & RadioButtonList1.SelectedItem.Text & _
            " with a value of : " & RadioButtonList1.SelectedItem.Value & "."
    End Sub
 
 </script>
 
 <head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
 
    <form id="form1" runat="server">
 
       <asp:RadioButtonList id="RadioButtonList1" 
            OnSelectedIndexChanged="Index_Changed"
            AutoPostBack="true"
            runat="server"/>
 
       <br />
 
       <asp:Label id="Label1" runat="server"/>
 
    </form>
 
 </body>
 </html>

備註

SelectedIndexChanged當清單控制項的選取範圍在貼文到伺服器之間變更時,就會引發 事件。

注意

清單控制項必須在貼文到伺服器之間保存一些值,此事件才能正常運作。 請確定清單控制項已啟用檢視狀態。

如需如何處理事件的詳細資訊,請參閱 處理和引發事件

適用於

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