DataGridSortCommandEventArgs.CommandSource 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 zdroj příkazu.
public:
property System::Object ^ CommandSource { System::Object ^ get(); };
public object CommandSource { get; }
member this.CommandSource : obj
Public ReadOnly Property CommandSource As Object
Hodnota vlastnosti
Zdroj příkazu.
Příklady
Následující příklad kódu ukazuje, jak použít CommandSource vlastnost k programovému řízení hlavičky v ovládacím DataGrid prvku.
<%@ 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">
<script runat="server">
ICollection CreateDataSource()
{
// Create a Random object to mix up the
// order of items in the sample data.
Random randNum = new Random();
// Create sample data for the DataGrid control.
DataTable dt = new DataTable();
// 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++)
{
DataRow dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + randNum.Next(1, 15).ToString();
dr[2] = 1.23 * randNum.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.
ItemsGrid.AllowSorting = AllowSortingCheckBox.Checked;
// 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>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>
ExtractTemplateRows Example
</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h3>DataGrid AllowSorting Example</h3>
<p>Select whether to allow sorting in the DataGrid control.<br />
<asp:CheckBox id="AllowSortingCheckBox"
Text="Allow sorting"
AutoPostBack="True"
Checked="True"
OnCheckedChanged="Check_Change"
runat="server"/></p>
<hr />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
OnSortCommand="Sort_Grid"
UseAccessibleHeader="true"
AutoGenerateColumns="False"
AllowSorting="True"
runat="server">
<HeaderStyle BackColor="#00aaaa" />
<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>
</div>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Function CreateDataSource() As ICollection
' Create a Random object to mix up the order
' of items in the sample data.
Dim randNum As Random = New Random()
' Create sample data for the DataGrid control.
Dim dt As DataTable = New DataTable()
' 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
Dim dr As DataRow = dt.NewRow()
dr(0) = i
dr(1) = "Item " & randNum.Next(1, 15).ToString()
dr(2) = 1.23 * randNum.Next(1, 15)
dt.Rows.Add(dr)
Next
' Persist the data source between posts to
' the server, in the session state.
Session("Source") = dt
Dim dv As DataView = New DataView(dt)
Return dv
End Function
Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Load sample data when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub
Sub Sort_Grid(ByVal sender As Object, _
ByVal 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(ByVal sender As Object, _
ByVal e As EventArgs)
' Allow or prevent sorting depending
' on the user's selection.
ItemsGrid.AllowSorting = _
AllowSortingCheckBox.Checked
' After changing the property, rebind
' the data to refresh the DataGrid control.
' Retrieve 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>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>
ExtractTemplateRows Example
</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h3>DataGrid AllowSorting Example</h3>
<p>Select whether to allow sorting in the DataGrid control.<br />
<asp:CheckBox id="AllowSortingCheckBox"
Text="Allow sorting"
AutoPostBack="True"
Checked="True"
OnCheckedChanged="Check_Change"
runat="server"/></p>
<hr />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
OnSortCommand="Sort_Grid"
UseAccessibleHeader="true"
AutoGenerateColumns="False"
AllowSorting="True"
runat="server">
<HeaderStyle BackColor="#00aaaa" />
<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>
</div>
</form>
</body>
</html>
Poznámky
CommandSource Pomocí vlastnosti získejte zdroj příkazu, který vyvolá SortCommand událost. Vzhledem k tomu, že tato událost je vyvolána pouze při kliknutí na odkaz v záhlaví DataGrid ovládacího prvku, vrácený zdroj je DataGridItem objekt, který představuje hlavičku. Tato vlastnost se dá použít k programovému řízení hlavičky.
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