DataGridPageChangedEventArgs.CommandSource Proprietà
Definizione
Importante
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Ottiene l'origine del comando.
public:
property System::Object ^ CommandSource { System::Object ^ get(); };public object CommandSource { get; }member this.CommandSource : objPublic ReadOnly Property CommandSource As ObjectValore della proprietà
Origine del comando.
Esempio
Nell'esempio di codice seguente viene illustrato come utilizzare la CommandSource proprietà per controllare a livello di codice l'origine del comando che genera l'evento .
<%@ Page Language="C#" %>
<%@ 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">
private 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)));
// Populate the table with sample values.
for (int i = 0; i <= 100; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = 1.23 * (i + 1);
dt.Rows.Add(dr);
}
DataView dv = new DataView(dt);
return dv;
}
private 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();
}
}
private void Check_Change(Object sender, EventArgs e)
{
// Allow or prevent paging depending
// on the user's selection.
ItemsGrid.AllowPaging = AllowPagingCheckBox.Checked;
// Rebind the data to refresh the DataGrid control.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
private void Grid_Change(Object sender, DataGridPageChangedEventArgs e)
{
// For the DataGrid control to navigate to the correct page when
// paging is allowed, the CurrentPageIndex property must be updated
// programmatically. This process is usually accomplished in the
// event-handling method for the PageIndexChanged event.
// Set CurrentPageIndex to the page the user clicked.
ItemsGrid.CurrentPageIndex = e.NewPageIndex;
// Rebind the data to refresh the DataGrid control.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>DataGrid AllowPaging Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h3>DataGrid AllowPaging Example</h3>
<p>Select whether to allow paging in the DataGrid control.<br />
<asp:CheckBox id="AllowPagingCheckBox"
Text="Allow paging"
AutoPostBack="True"
Checked="True"
OnCheckedChanged="Check_Change"
runat="server" />
</p>
<hr />
<asp:Label runat="server"
AssociatedControlID="ItemsGrid"
Font-Bold="true">Product List</asp:Label>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="Gray"
BorderWidth="1"
CellPadding="3"
AutoGenerateColumns="False"
UseAccessibleHeader="true"
PageSize="10"
AllowPaging="True"
OnPageIndexChanged="Grid_Change">
<HeaderStyle BackColor="LightBlue" />
<Columns>
<asp:BoundColumn DataField="IntegerValue"
SortExpression="IntegerValue"
ItemStyle-HorizontalAlign="center"
HeaderText="Item" />
<asp:BoundColumn DataField="StringValue"
HeaderText="Description"
ItemStyle-HorizontalAlign="left"
SortExpression="StringValue" />
<asp:BoundColumn DataField="CurrencyValue"
HeaderText="Price"
SortExpression="CurrencyValue"
DataFormatString="{0:c}" />
</Columns>
<ItemStyle HorizontalAlign="Right" />
</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 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 100
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = 1.23 * (i + 1)
dt.Rows.Add(dr)
Next i
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 only once, when the page is first loaded.
If Not IsPostBack Then
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub
Sub Check_Change(ByVal sender As Object, ByVal e As EventArgs)
' Allow or prevent paging depending on the user's selection.
ItemsGrid.AllowPaging = AllowPagingCheckBox.Checked()
' Rebind the data to refresh the DataGrid control.
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End Sub
Sub Grid_Change(ByVal sender As Object, ByVal e As DataGridPageChangedEventArgs)
' For the DataGrid control to navigate to the correct page when
' paging is allowed, the CurrentPageIndex property must be updated
' programmatically. This process is usually accomplished in the
' event-handling method for the PageIndexChanged event.
' Set CurrentPageIndex to the page the user clicked.
ItemsGrid.CurrentPageIndex = e.NewPageIndex
' Rebind the data to refresh the DataGrid control.
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head2" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<h3>DataGrid AllowPaging Example</h3>
<p>Select whether to allow paging in the DataGrid control.<br />
<asp:CheckBox id="AllowPagingCheckBox"
Text="Allow paging"
AutoPostBack="True"
Checked="True"
OnCheckedChanged="Check_Change"
runat="server" />
</p>
<hr />
<asp:Label ID="Label1" runat="server"
AssociatedControlID="ItemsGrid"
Font-Bold="true">Product List</asp:Label>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="Gray"
BorderWidth="1"
CellPadding="3"
UseAccessibleHeader="true"
AutoGenerateColumns="False"
PageSize="10"
AllowPaging="True"
OnPageIndexChanged="Grid_Change">
<HeaderStyle BackColor="LightBlue" />
<Columns>
<asp:BoundColumn DataField="IntegerValue"
SortExpression="IntegerValue"
ItemStyle-HorizontalAlign="center"
HeaderText="Item" />
<asp:BoundColumn DataField="StringValue"
HeaderText="Description"
ItemStyle-HorizontalAlign="left"
SortExpression="StringValue" />
<asp:BoundColumn DataField="CurrencyValue"
HeaderText="Price"
SortExpression="CurrencyValue"
DataFormatString="{0:c}" />
</Columns>
<ItemStyle HorizontalAlign="Right" />
</asp:DataGrid>
</div>
</form>
</body>
</html>
Commenti
Utilizzare la CommandSource proprietà per determinare l'origine del comando che ha generato l'evento. Poiché questo evento viene generato solo quando si fa clic su un pulsante nell'elemento di selezione della pagina del DataGrid controllo , l'origine restituita è un DataGridItem oggetto che rappresenta l'elemento di selezione della pagina.
Si applica a
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