DataGrid.SelectedIndex Vlastnost
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Získá nebo nastaví index vybrané položky v ovládacím DataGrid prvku.
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, setPublic Overridable Property SelectedIndex As IntegerHodnota vlastnosti
Index vybrané položky v ovládacím DataGrid prvku.
- Atributy
Výjimky
Zadaný index je menší než -1.
Příklady
Následující příklad kódu ukazuje, jak použít SelectedIndex vlastnost k určení indexu číslo vybrané položky v ovládacím DataGrid prvku. Také ukazuje, jak vybrat a zrušit výběr položky prostřednictvím kódu programu.
<%@ 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>
Poznámky
SelectedIndex Pomocí vlastnosti určete index položky vybrané uživatelem v ovládacím DataGrid prvku. Tuto vlastnost můžete použít také k programovému určení, která položka je vybrána v ovládacím DataGrid prvku.
Pokud chcete zrušit výběr položky v ovládacím DataGrid prvku, nastavte tuto vlastnost na -1.