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DataGrid.SelectedIndex-Eigenschaft

  • Artikel

Ruft den Index des ausgewählten Elements im DataGrid-Steuerelement ab oder legt diesen fest.

Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)

Syntax

'Declaration
<BindableAttribute(True)> _
Public Overridable Property SelectedIndex As Integer
'Usage
Dim instance As DataGrid
Dim value As Integer

value = instance.SelectedIndex

instance.SelectedIndex = value

[BindableAttribute(true)] 
public virtual int SelectedIndex { get; set; }

[BindableAttribute(true)] 
public:
virtual property int SelectedIndex {
    int get ();
    void set (int value);
}

/** @property */
public int get_SelectedIndex ()

/** @property */
public void set_SelectedIndex (int value)

public function get SelectedIndex () : int

public function set SelectedIndex (value : int)

Eigenschaftenwert

Der Index des ausgewählten Elements im DataGrid-Steuerelement.

Ausnahmen

Ausnahmetyp Bedingung

ArgumentOutOfRangeException

Der angegebene Index ist kleiner als -1.

Hinweise

Bestimmen Sie mit der SelectedIndex-Eigenschaft den Index des vom Benutzer im DataGrid-Steuerelement ausgewählten Elements. Sie können mit dieser Eigenschaft auch programmgesteuert festlegen, welches Element im DataGrid-Steuerelement ausgewählt ist.

Um die Auswahl eines Elements im DataGrid-Steuerelement aufzuheben, legen Sie diese Eigenschaft auf -1 fest.

Beispiel

Das folgende Codebeispiel veranschaulicht, wie Sie mit der SelectedIndex-Eigenschaft die Indexnummer des im DataGrid-Steuerelement ausgewählten Elements bestimmen. Es zeigt auch, wie ein Element programmgesteuert ausgewählt und die Auswahl wieder aufgehoben wird.

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

   <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>
 
<body>
 
   <form runat="server">

      <h3>DataGrid Selection Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Name="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="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<html>

   <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>
 
<body>
 
   <form runat="server">

      <h3>DataGrid Selection Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Name="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="JScript" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<html>

   <script language="JScript" runat="server">
 
      var Cart : DataTable = new DataTable();
      var CartView : DataView;   
 
      function Page_Load(sender, e : EventArgs) 
      {
         var dr : DataRow;
 
         if (Session["ShoppingCart"] == null) 
         {       
            Cart.Columns.Add(new DataColumn("Qty", System.String));
            Cart.Columns.Add(new DataColumn("Item", System.String));
            Cart.Columns.Add(new DataColumn("Price", System.String));
            Session["ShoppingCart"] = Cart;
             
            // Create rows and add sample data.
            for (var i : int = 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();                    
      }
 
      function MyDataGrid_Select(sender, e : EventArgs) 
      {
 
         Label1.Text = "You selected " +
                       MyDataGrid.SelectedItem.Cells[1].Text +
                       ".<br>" + 
                       MyDataGrid.SelectedItem.Cells[1].Text +
                       " has an index number of " +
                       MyDataGrid.SelectedIndex.ToString() + ".";
                                
      }

      function Select_Button_Click(sender, e : EventArgs) 
      {
 
         MyDataGrid.SelectedIndex = 4;
                                
      }

      function UnSelect_Button_Click(sender, e : EventArgs) 
      {
 
         MyDataGrid.SelectedIndex = -1;
         Label1.Text = "";
                                
      }
 
      function BindGrid() 
      {
         MyDataGrid.DataSource = CartView;
         MyDataGrid.DataBind();
      } 
 
   </script>
 
<body>
 
   <form runat="server">

      <h3>DataGrid Selection Example</h3>
 
      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           Font-Name="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>

Plattformen

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.

Versionsinformationen

.NET Framework

Unterstützt in: 2.0, 1.1, 1.0

Siehe auch

Referenz

DataGrid-Klasse
DataGrid-Member
System.Web.UI.WebControls-Namespace