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DataGrid.SelectedIndex 屬性

定義

取得或設定 DataGrid 控制項中選取之項目的索引。

public:
 virtual property int SelectedIndex { int get(); void set(int value); };
[System.ComponentModel.Bindable(true)]
public virtual int SelectedIndex { get; set; }
[<System.ComponentModel.Bindable(true)>]
member this.SelectedIndex : int with get, set
Public Overridable Property SelectedIndex As Integer

屬性值

Int32

DataGrid 控制項中選取之項目的索引。

屬性

例外狀況

指定的索引小於 -1。

範例

下列程式碼範例示範如何使用 SelectedIndex 屬性來判斷 控制項中 DataGrid 所選項目的索引編號。 它也會示範如何以程式設計方式選取和取消選取專案。

<%@ 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">
 
      DataTable Cart = new DataTable();
      DataView CartView;   
 
      void Page_Load(Object sender, EventArgs e) 
      {
         DataRow dr;
 
         if (Session["ShoppingCart"] == null) 
         {       
            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["ShoppingCart"] = Cart;
             
            // Create rows and add sample data.
            for (int i = 1; i <= 9; i++) 
            {
               dr = Cart.NewRow();
               if (i % 2 != 0)
                  dr[0] = "2";
               else
                  dr[0] = "1";
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1)).ToString();
               Cart.Rows.Add(dr);
            }
         }
         else
            Cart = (DataTable)Session["ShoppingCart"];          
 
         CartView = new DataView(Cart);
         CartView.Sort="Item";
 
         if (!IsPostBack)
            BindGrid();                    
      }
 
      void MyDataGrid_Select(Object sender, EventArgs e) 
      {
 
         Label1.Text = "You selected " +
                       MyDataGrid.SelectedItem.Cells[1].Text +
                       ".<br />" + 
                       MyDataGrid.SelectedItem.Cells[1].Text +
                       " has an index number of " +
                       MyDataGrid.SelectedIndex.ToString() + ".";
                                
      }

      void Select_Button_Click(Object sender, EventArgs e) 
      {
 
         MyDataGrid.SelectedIndex = 4;
                                
      }

      void UnSelect_Button_Click(Object sender, EventArgs e) 
      {
 
         MyDataGrid.SelectedIndex = -1;
         Label1.Text = "";
                                
      }
 
      void BindGrid() 
      {
         MyDataGrid.DataSource = CartView;
         MyDataGrid.DataBind();
      } 
 
   </script>
 
<head runat="server">
    <title>DataGrid Selection Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Selection Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Names="Verdana"
           Font-Size="8pt"
           OnSelectedIndexChanged="MyDataGrid_Select"
           AutoGenerateColumns="false">

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

         <SelectedItemStyle BackColor="Yellow">
         </SelectedItemStyle>
 
         <Columns>

            <asp:ButtonColumn
                 HeaderText="Select Item"
                 ButtonType="LinkButton"
                 Text="Select"
                 CommandName="Select">

            </asp:ButtonColumn>
 
            <asp:BoundColumn 
                 HeaderText="Item" 
                 ReadOnly="true" 
                 DataField="Item"/>

            <asp:BoundColumn 
                 HeaderText="Quantity" 
                 DataField="Qty"/>

            <asp:BoundColumn 
                 HeaderText="Price" 
                 DataField="Price"/>

         </Columns>

      </asp:DataGrid>

      <br /><br />

      <asp:Button id="Button1"
           Text="Select Item 5"
           OnClick="Select_Button_Click"
           runat="server"/>

      <asp:Button id="Button2"
           Text="Unselect Item"
           OnClick="UnSelect_Button_Click"
           runat="server"/>

      <br /><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">
 
        Dim Cart As New DataTable
        Dim CartView As DataView
        
        Sub Page_Load(sender As Object, e As EventArgs)
            Dim dr As DataRow
            
            If Session("ShoppingCart") Is Nothing Then
                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("ShoppingCart") = Cart
                
                ' Create rows and add sample data.
                Dim i As Integer
                For i = 1 To 9
                    dr = Cart.NewRow()
                    If i Mod 2 <> 0 Then
                        dr(0) = "2"
                    Else
                        dr(0) = "1"
                    End If
                    dr(1) = "Item " & i.ToString()
                    dr(2) =(1.23 *(i + 1)).ToString()
                    Cart.Rows.Add(dr)
                Next i
            Else
                Cart = CType(Session("ShoppingCart"), DataTable)
            End If 
            CartView = New DataView(Cart)
            CartView.Sort = "Item"
            
            If Not IsPostBack Then
                BindGrid()
            End If
        End Sub 'Page_Load
         
        Sub MyDataGrid_Select(sender As Object, e As EventArgs)
            
            Label1.Text = "You selected " & MyDataGrid.SelectedItem.Cells(1).Text & _
                ".<br />" & MyDataGrid.SelectedItem.Cells(1).Text & " has an index number of " & _
                MyDataGrid.SelectedIndex.ToString() & "."
        End Sub 'MyDataGrid_Select

        Sub Select_Button_Click(sender As Object, e As EventArgs)
            
            MyDataGrid.SelectedIndex = 4
        End Sub 'Select_Button_Click
         
        Sub UnSelect_Button_Click(sender As Object, e As EventArgs)
            
            MyDataGrid.SelectedIndex = - 1
            Label1.Text = ""
        End Sub 'UnSelect_Button_Click
         
        Sub BindGrid()
            MyDataGrid.DataSource = CartView
            MyDataGrid.DataBind()
        End Sub 'BindGrid
 
   </script>
 
<head runat="server">
    <title>DataGrid Selection Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataGrid Selection Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Names="Verdana"
           Font-Size="8pt"
           OnSelectedIndexChanged="MyDataGrid_Select"
           AutoGenerateColumns="false">

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

         <SelectedItemStyle BackColor="Yellow">
         </SelectedItemStyle>
 
         <Columns>

            <asp:ButtonColumn
                 HeaderText="Select Item"
                 ButtonType="LinkButton"
                 Text="Select"
                 CommandName="Select">

            </asp:ButtonColumn>
 
            <asp:BoundColumn 
                 HeaderText="Item" 
                 ReadOnly="true" 
                 DataField="Item"/>

            <asp:BoundColumn 
                 HeaderText="Quantity" 
                 DataField="Qty"/>

            <asp:BoundColumn 
                 HeaderText="Price" 
                 DataField="Price"/>

         </Columns>

      </asp:DataGrid>

      <br /><br />

      <asp:Button id="Button1"
           Text="Select Item 5"
           OnClick="Select_Button_Click"
           runat="server"/>

      <asp:Button id="Button2"
           Text="Unselect Item"
           OnClick="UnSelect_Button_Click"
           runat="server"/>

      <br /><br />

      <asp:Label id="Label1" runat="server"/> 
 
   </form>
 
</body>
</html>

備註

SelectedIndex使用 屬性來判斷 控制項中 DataGrid 使用者所選取專案的索引。 您也可以使用這個屬性,以程式設計方式指定控制項中 DataGrid 選取的專案。

若要取消選取 控制項中的 DataGrid 專案,請將此屬性設定為 -1。

適用於