DataGrid.SelectedIndex 属性

定义

获取或设置 DataGrid 控件中的选定项的索引。Gets or sets the index of the selected item in the DataGrid control.

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

属性值

DataGrid 控件中的选定项的索引。The index of the selected item in the DataGrid control.

属性

异常

指定的索引小于 -1。The specified index is less than -1.

示例

下面的代码示例演示如何使用 SelectedIndex 属性确定 DataGrid 控件中选定项的索引号。The following code example demonstrates how to use the SelectedIndex property to determine the index number of the selected item in the DataGrid control. 它还演示如何以编程方式选择和取消选择项。It also shows how to select and deselect an item programmatically.

<%@ 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>

注解

使用 SelectedIndex 属性可确定用户在 DataGrid 控件中选定的项的索引。Use the SelectedIndex property to determine the index of the item selected by the user in the DataGrid control. 你还可以使用此属性以编程方式指定 DataGrid 控件中选择的项。You can also use this property to programmatically specify which item is selected in the DataGrid control.

若要取消选择 DataGrid 控件中的项,请将此属性设置为-1。To deselect an item in the DataGrid control, set this property to -1.

适用于