DataGridSortCommandEventArgs.CommandSource-Eigenschaft
Ruft die Quelle des Befehls ab.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Public ReadOnly Property CommandSource As Object
'Usage
Dim instance As DataGridSortCommandEventArgs
Dim value As Object
value = instance.CommandSource
public Object CommandSource { get; }
public:
property Object^ CommandSource {
Object^ get ();
}
/** @property */
public Object get_CommandSource ()
public function get CommandSource () : Object
Eigenschaftenwert
Die Quelle des Befehls.
Hinweise
Verwenden Sie die CommandSource-Eigenschaft, um die Befehlsquelle abzurufen, die das SortCommand-Ereignis auslöst. Dieses Ereignis wird nur beim Klicken auf eine Verknüpfung in der Kopfzeile des DataGrid-Steuerelements ausgelöst. Daher ist die zurückgegebene Quelle ein DataGridItem-Objekt, das die Kopfzeile darstellt. Mit dieser Eigenschaft kann die Kopfzeile programmgesteuert festgelegt werden.
Beispiel
Im folgenden Codebeispiel wird veranschaulicht, wie mit der CommandSource-Eigenschaft die Kopfzeile im DataGrid-Steuerelement programmgesteuert festgelegt wird.
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script runat="server">
Function CreateDataSource() As ICollection
' Create a Random object to mix up the order of items in the
' sample data.
Dim Rand_Num As Random = New Random()
' 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(Int32)))
dt.Columns.Add(new DataColumn("StringValue", GetType(String)))
dt.Columns.Add(new DataColumn("CurrencyValue", GetType(Double)))
' Populate the table with sample values.
Dim i As Integer
For i = 0 To 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & Rand_Num.Next(1, 15).ToString()
dr(2) = 1.23 * Rand_Num.Next(1, 15)
dt.Rows.Add(dr)
Next i
' 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 Sort_Grid(sender As Object, e As DataGridSortCommandEventArgs)
' Retrieve the data source from session state.
Dim dt As DataTable = CType(Session("Source"), DataTable)
' Create a DataView from the DataTable.
Dim dv As DataView = New DataView(dt)
' The DataView provides an easy way to sort. Simply set the
' Sort property with the name of the field to sort by.
dv.Sort = e.SortExpression
' Rebind the data source and specify that it should be sorted
' by the field specified in the SortExpression property.
ItemsGrid.DataSource = dv
ItemsGrid.DataBind()
End Sub
Sub Check_Change(sender As Object, e As EventArgs)
' Allow or prevent sorting depending on the user's selection.
If AllowSortingCheckBox.Checked Then
ItemsGrid.AllowSorting = True
Else
ItemsGrid.AllowSorting = False
End If
' After changing the property, rebind the data to
' refresh the DataGrid control.
' Retrieve the data source from session state.
Dim dt As DataTable = CType(Session("Source"), DataTable)
' Create a DataView from the DataTable.
Dim dv As DataView = New DataView(dt)
' Rebind the data source.
ItemsGrid.DataSource = dv
ItemsGrid.DataBind()
End Sub
</script>
<body>
<form runat=server>
<h3>DataGrid AllowSorting Example</h3>
Select whether to allow sorting in the DataGrid control.
<br><br>
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
OnSortCommand="Sort_Grid"
AutoGenerateColumns="False"
AllowSorting="True"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<Columns>
<asp:BoundColumn DataField="IntegerValue"
SortExpression="IntegerValue"
HeaderText="Item"/>
<asp:BoundColumn DataField="StringValue"
SortExpression="StringValue"
HeaderText="Description"/>
<asp:BoundColumn DataField="CurrencyValue"
HeaderText="Price"
SortExpression="CurrencyValue"
DataFormatString="{0:c}">
<ItemStyle HorizontalAlign="Right">
</ItemStyle>
</asp:BoundColumn>
</Columns>
</asp:DataGrid>
<hr>
<asp:CheckBox id="AllowSortingCheckBox"
Text="Allow sorting"
AutoPostBack="True"
Checked="True"
OnCheckedChanged="Check_Change"
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script runat="server">
ICollection CreateDataSource()
{
// Create a Random object to mix up the order of items in the
// sample data.
Random Rand_Num = new Random();
// 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)));
// Populate the table with sample values.
for (int i=0; i<=8; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + Rand_Num.Next(1, 15).ToString();
dr[2] = 1.23 * Rand_Num.Next(1, 15);
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 Sort_Grid(Object sender, DataGridSortCommandEventArgs e)
{
// Retrieve the data source from session state.
DataTable dt = (DataTable)Session["Source"];
// Create a DataView from the DataTable.
DataView dv = new DataView(dt);
// The DataView provides an easy way to sort. Simply set the
// Sort property with the name of the field to sort by.
dv.Sort = e.SortExpression;
// Rebind the data source and specify that it should be sorted
// by the field specified in the SortExpression property.
ItemsGrid.DataSource = dv;
ItemsGrid.DataBind();
}
void Check_Change(Object sender, EventArgs e)
{
// Allow or prevent sorting depending on the user's selection.
if (AllowSortingCheckBox.Checked)
{
ItemsGrid.AllowSorting = true;
}
else
{
ItemsGrid.AllowSorting = false;
}
// After changing the property, rebind the data to
// refresh the DataGrid control.
// Retrieve the data source from session state.
DataTable dt = (DataTable)Session["Source"];
// Create a DataView from the DataTable.
DataView dv = new DataView(dt);
// Rebind the data source.
ItemsGrid.DataSource = dv;
ItemsGrid.DataBind();
}
</script>
<body>
<form runat=server>
<h3>DataGrid AllowSorting Example</h3>
Select whether to allow sorting in the DataGrid control.
<br><br>
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
OnSortCommand="Sort_Grid"
AutoGenerateColumns="False"
AllowSorting="True"
runat="server">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<Columns>
<asp:BoundColumn DataField="IntegerValue"
SortExpression="IntegerValue"
HeaderText="Item"/>
<asp:BoundColumn DataField="StringValue"
SortExpression="StringValue"
HeaderText="Description"/>
<asp:BoundColumn DataField="CurrencyValue"
HeaderText="Price"
SortExpression="CurrencyValue"
DataFormatString="{0:c}">
<ItemStyle HorizontalAlign="Right">
</ItemStyle>
</asp:BoundColumn>
</Columns>
</asp:DataGrid>
<hr>
<asp:CheckBox id="AllowSortingCheckBox"
Text="Allow sorting"
AutoPostBack="True"
Checked="True"
OnCheckedChanged="Check_Change"
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
DataGridSortCommandEventArgs-Klasse
DataGridSortCommandEventArgs-Member
System.Web.UI.WebControls-Namespace
DataGrid-Klasse
DataGrid.SortCommand-Ereignis