DataKeyCollection.Item[Int32] Özellik
Tanım
Önemli
Bazı bilgiler ürünün ön sürümüyle ilgilidir ve sürüm öncesinde önemli değişiklikler yapılmış olabilir. Burada verilen bilgilerle ilgili olarak Microsoft açık veya zımni hiçbir garanti vermez.
Koleksiyonda belirtilen dizindeki anahtar alanını alır.
public:
property System::Object ^ default[int] { System::Object ^ get(int index); };public object this[int index] { get; }member this.Item(int) : objDefault Public ReadOnly Property Item(index As Integer) As ObjectParametreler
- index
- Int32
Koleksiyondan alınacak anahtar alanının sıfır tabanlı dizini.
Özellik Değeri
Koleksiyonda belirtilen dizindeki anahtar alanı.
Örnekler
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>
<!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" >
<head runat="server">
<title>BaseDataList DataKeys Example</title>
<script runat="server">
ICollection CreateDataSource()
{
// Create sample data for the DataGrid control.
DataTable dt = new DataTable();
DataRow dr;
// Define the columns of the table.
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
// Define the primary key for the table as the IntegerValue
// column (column 0). To do this, first create an array of
// DataColumns to represent the primary key. The primary key can
// consist of multiple columns, but in this example, only
// one column is used.
DataColumn[] keys = new DataColumn[1];
keys[0] = dt.Columns[0];
// Then assign the array to the PrimaryKey property of the DataTable.
dt.PrimaryKey = keys;
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * (i + 1);
dt.Rows.Add(dr);
}
// To persist the data source between posts to the server,
// store it in session state.
Session["Source"] = dt;
DataView dv = new DataView(dt);
return dv;
}
void Page_Load(Object sender, EventArgs e)
{
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void Delete_Command(Object sender, DataGridCommandEventArgs e)
{
// Retrieve the data table from session state.
DataTable dt = (DataTable)Session["Source"];
// Retrieve the data row to delete from the data table.
// Use the DataKeys property of the DataGrid control to get
// the primary key value of the selected row.
// Search the Rows collection of the data table for this value.
DataRow row;
row = dt.Rows.Find(ItemsGrid.DataKeys[e.Item.ItemIndex]);
// Delete the item selected in the DataGrid from the data source.
if(row != null)
{
dt.Rows.Remove(row);
}
// Save the data source.
Session["Source"] = dt;
// Create a DataView and bind it to the DataGrid control.
DataView dv = new DataView(dt);
ItemsGrid.DataSource = dv;
ItemsGrid.DataBind();
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>BaseDataList DataKeys Example</h3>
<asp:DataGrid id="ItemsGrid"
BorderColor="Black"
ShowFooter="False"
CellPadding="3"
CellSpacing="0"
HeaderStyle-BackColor="#aaaadd"
DataKeyField="IntegerValue"
OnDeleteCommand="Delete_Command"
runat="server">
<Columns>
<asp:ButtonColumn Text="Delete"
CommandName="Delete"/>
</Columns>
</asp:DataGrid>
</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" >
<head runat="server">
<title>BaseDataList DataKeys and DataKeyField Example</title>
<script runat="server">
Function CreateDataSource() As ICollection
' Create sample data for the DataGrid control.
Dim dt As DataTable = New DataTable()
Dim dr As DataRow
' Define the columns of the table.
dt.Columns.Add(new DataColumn("IntegerValue", GetType(Integer)))
dt.Columns.Add(new DataColumn("StringValue", GetType(String)))
dt.Columns.Add(new DataColumn("CurrencyValue", GetType(Double)))
' Define the primary key for the table as the IntegerValue
' column (column 0). To do this, first create an array of
' DataColumns to represent the primary key. The primary key can
' consist of multiple columns, but in this example, only
' one column is used.
Dim keys(1) As DataColumn
keys(0) = dt.Columns(0)
' Then assign the array to the PrimaryKey property of the DataTable.
dt.PrimaryKey = keys
' Populate the table with sample values.
Dim i As Integer
For i = 0 To 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * (i + 1)
dt.Rows.Add(dr)
Next
' To persist the data source between posts to the server,
' store it in session state.
Session("Source") = dt
Dim dv As DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(sender As Object, e As EventArgs)
' Load sample data only once, when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub
Sub Delete_Command(sender As Object, e As DataGridCommandEventArgs)
' Retrieve the data table from session state.
Dim dt As DataTable = CType(Session("Source"), DataTable)
' Retrieve the data row to delete from the data table.
' Use the DataKeys property of the DataGrid control to get
' the primary key value of the selected row.
' Search the Rows collection of the data table for this value.
Dim row As DataRow
row = dt.Rows.Find(ItemsGrid.DataKeys(e.Item.ItemIndex))
' Delete the item selected in the DataGrid from the data source.
If Not row is Nothing Then
dt.Rows.Remove(row)
End If
' Save the data source.
Session("Source") = dt
' Create a DataView and bind it to the DataGrid control.
Dim dv As DataView = New DataView(dt)
ItemsGrid.DataSource = dv
ItemsGrid.DataBind()
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>BaseDataList DataKeys and DataKeyField Example</h3>
<asp:DataGrid id="ItemsGrid"
BorderColor="Black"
ShowFooter="False"
CellPadding="3"
CellSpacing="0"
HeaderStyle-BackColor="#aaaadd"
DataKeyField="IntegerValue"
OnDeleteCommand="Delete_Command"
runat="server">
<Columns>
<asp:ButtonColumn Text="Delete"
CommandName="Delete"/>
</Columns>
</asp:DataGrid>
</form>
</body>
</html>
Açıklamalar
Dizi gösterimini kullanarak belirtilen dizindeki anahtar alanını DataKeyCollection almak için bu dizin oluşturucuyu kullanın.