DataGrid.AllowSorting-Eigenschaft
Ruft einen Wert ab, der angibt, ob das Sortieren aktiviert ist, oder legt diesen fest.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Public Overridable Property AllowSorting As Boolean
'Usage
Dim instance As DataGrid
Dim value As Boolean
value = instance.AllowSorting
instance.AllowSorting = value
public virtual bool AllowSorting { get; set; }
public:
virtual property bool AllowSorting {
bool get ();
void set (bool value);
}
/** @property */
public boolean get_AllowSorting ()
/** @property */
public void set_AllowSorting (boolean value)
public function get AllowSorting () : boolean
public function set AllowSorting (value : boolean)
Eigenschaftenwert
true, wenn das Sortieren aktiviert ist, andernfalls false. Der Standardwert ist false.
Hinweise
Wenn das Sortieren aktiviert ist, werden LinkButton-Steuerelemente im Headerzeilenbereich aller Spalten dargestellt, in denen die SortExpression-Eigenschaft festgelegt ist. Mit diesen LinkButton-Steuerelementen können Sie das DataGrid-Steuerelement nach der ausgewählten Spalte sortieren. Die einzige Ausnahme besteht in der Verwendung eines TemplateColumn-Spaltentyps, für den die HeaderTemplate-Eigenschaft festgelegt ist. In diesem Fall müssen Sie ein Button-Steuerelement in der HeaderTemplate der Spalte angeben.
Das SortCommand-Ereignis wird ausgelöst, wenn auf eines der LinkButton-Steuerelemente geklickt wird. Code für den Ereignishandler muss von Ihnen angegeben werden. Die übliche Handlerlogik besteht darin, die Liste zu sortieren und anschließend die Daten erneut an das DataGrid-Steuerelement zu binden.
Beispiel
Das folgende Codebeispiel veranschaulicht die Aktivierung des Sortierens mithilfe der AllowSorting-Eigenschaft.
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script language="VB" runat="server">
Dim SortExpression As String
Function CreateDataSource() As ICollection
Dim dt As New DataTable()
Dim dr As DataRow
Dim Rand_Num As New Random()
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
Dim i As Integer
For i = 0 To 14
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * Rand_Num.Next(1, 15)
dt.Rows.Add(dr)
Next i
Dim dv As New DataView(dt)
dv.Sort = SortExpression
Return dv
End Function 'CreateDataSource
Sub Page_Load(sender As Object, e As EventArgs)
If Not IsPostBack Then
If SortExpression = "" Then
SortExpression = "IntegerValue"
End If
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub 'Page_Load
Sub Sort_Grid(sender As Object, e As DataGridSortCommandEventArgs)
SortExpression = e.SortExpression.ToString()
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End Sub 'Sort_Grid
</script>
<body>
<form runat=server>
<h3>DataGrid Sorting Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
AllowSorting="true"
OnSortCommand="Sort_Grid"
HeaderStyle-BackColor="#00aaaa"
AutoGenerateColumns="true"/>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script language="C#" runat="server">
string SortExpression;
ICollection CreateDataSource()
{
DataTable dt = new DataTable();
DataRow dr;
Random Rand_Num = new Random();
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
for (int i = 0; i < 15; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * Rand_Num.Next(1, 15);
dt.Rows.Add(dr);
}
DataView dv = new DataView(dt);
dv.Sort=SortExpression;
return dv;
}
void Page_Load(Object sender, EventArgs e)
{
if (!IsPostBack)
{
if (SortExpression == "")
SortExpression = "IntegerValue";
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void Sort_Grid(Object sender, DataGridSortCommandEventArgs e)
{
SortExpression = e.SortExpression.ToString();
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
</script>
<body>
<form runat=server>
<h3>DataGrid Sorting Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
AllowSorting="true"
OnSortCommand="Sort_Grid"
HeaderStyle-BackColor="#00aaaa"
AutoGenerateColumns="true"/>
</form>
</body>
</html>
<%@ Page Language="JScript" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script language="JScript" runat="server">
var SortExpression : String;
function CreateDataSource () : ICollection
{
var dt : DataTable = new DataTable();
var dr : DataRow;
var Rand_Num : Random = new Random();
dt.Columns.Add(new DataColumn("IntegerValue", Int32));
dt.Columns.Add(new DataColumn("StringValue", System.String));
dt.Columns.Add(new DataColumn("CurrencyValue", double));
for (var i : int = 0; i < 15; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * Rand_Num.Next(1, 15);
dt.Rows.Add(dr);
}
var dv : DataView = new DataView(dt);
dv.Sort=SortExpression;
return dv;
}
function Page_Load(sender, e : EventArgs)
{
if (!IsPostBack)
{
if (SortExpression == "")
SortExpression = "IntegerValue";
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
function Sort_Grid(sender, e : DataGridSortCommandEventArgs)
{
SortExpression = e.SortExpression.ToString();
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
</script>
<body>
<form runat=server>
<h3>DataGrid Sorting Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
AllowSorting="true"
OnSortCommand="Sort_Grid"
HeaderStyle-BackColor="#00aaaa"
AutoGenerateColumns="true"/>
</form>
</body>
</html>
<%@ 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
DataGrid-Klasse
DataGrid-Member
System.Web.UI.WebControls-Namespace
SortCommand
LinkButton
Button-Klasse
TemplateColumn
HeaderTemplate