DataGrid.PageSize Proprietà
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Ottiene o imposta il numero di elementi da visualizzare su una singola pagina del controllo DataGrid.
public:
virtual property int PageSize { int get(); void set(int value); };
public virtual int PageSize { get; set; }
member this.PageSize : int with get, set
Public Overridable Property PageSize As Integer
Valore della proprietà
Il numero di elementi da visualizzare su una singola pagina del controllo DataGrid. Il valore predefinito è 10.
Eccezioni
La dimensione specificata per la pagina è minore di 1.
Esempio
Nell'esempio di codice seguente viene illustrato come usare la PageSize proprietà per specificare che cinque elementi vengono visualizzati in una singola pagina del DataGrid controllo.
<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<script language="C#" runat="server">
ICollection CreateDataSource()
{
DataTable dt = new DataTable();
DataRow dr;
dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
dt.Columns.Add(new DataColumn("DateTimeValue", typeof(string)));
dt.Columns.Add(new DataColumn("BoolValue", typeof(bool)));
for (int i = 0; i < 100; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Item " + i.ToString();
dr[2] = DateTime.Now.ToShortDateString();
dr[3] = (i % 2 != 0) ? true : false;
dt.Rows.Add(dr);
}
DataView dv = new DataView(dt);
return dv;
}
void Page_Load(Object sender, EventArgs e)
{
if (chk1.Checked)
MyDataGrid.PagerStyle.Mode = PagerMode.NumericPages;
else
MyDataGrid.PagerStyle.Mode = PagerMode.NextPrev;
BindGrid();
}
void MyDataGrid_Page(Object sender, DataGridPageChangedEventArgs e)
{
MyDataGrid.CurrentPageIndex = e.NewPageIndex;
BindGrid();
}
void BindGrid()
{
MyDataGrid.DataSource = CreateDataSource();
MyDataGrid.DataBind();
ShowStats();
}
void ShowStats()
{
lblEnabled.Text = "AllowPaging is " + MyDataGrid.AllowPaging;
lblCurrentIndex.Text = "CurrentPageIndex is " + MyDataGrid.CurrentPageIndex;
lblPageCount.Text = "PageCount is " + MyDataGrid.PageCount;
lblPageSize.Text = "PageSize is " + MyDataGrid.PageSize;
}
</script>
<head runat="server">
<title>DataGrid Paging Example</title>
</head>
<body>
<h3>DataGrid Paging Example</h3>
<form id="form1" runat="server">
<asp:DataGrid id="MyDataGrid" runat="server"
AllowPaging="True"
PageSize="10"
OnPageIndexChanged="MyDataGrid_Page"
BorderColor="black"
BorderWidth="1"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
Font-Names="Verdana"
Font-Size="8pt">
<PagerStyle Mode="NumericPages"
HorizontalAlign="Right">
</PagerStyle>
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="#eeeeee">
</AlternatingItemStyle>
</asp:DataGrid>
<br />
<asp:Checkbox id="chk1" runat="server"
Text="Show numeric page navigation buttons"
Font-Names="Verdana"
Font-Size="8pt"
AutoPostBack="true"/>
<br />
<table style="background-color:#eeeeee; padding:6">
<tr>
<td style="display:inline">
<asp:Label id="lblEnabled"
runat="server"/><br />
<asp:Label id="lblCurrentIndex"
runat="server"/><br />
<asp:Label id="lblPageCount"
runat="server"/><br />
<asp:Label id="lblPageSize"
runat="server"/><br />
</td>
</tr>
</table>
</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" >
<script language="VB" runat="server">
Function CreateDataSource() As ICollection
Dim dt As New DataTable()
Dim dr As DataRow
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
dt.Columns.Add(New DataColumn("DateTimeValue", GetType(String)))
dt.Columns.Add(New DataColumn("BoolValue", GetType(Boolean)))
Dim i As Integer
For i = 0 To 99
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " & i.ToString()
dr(2) = DateTime.Now.ToShortDateString()
If i Mod 2 <> 0 Then
dr(3) = True
Else
dr(3) = False
End If
dt.Rows.Add(dr)
Next i
Dim dv As New DataView(dt)
Return dv
End Function 'CreateDataSource
Sub Page_Load(sender As Object, e As EventArgs)
If chk1.Checked Then
MyDataGrid.PagerStyle.Mode = PagerMode.NumericPages
Else
MyDataGrid.PagerStyle.Mode = PagerMode.NextPrev
End If
BindGrid()
End Sub 'Page_Load
Sub MyDataGrid_Page(sender As Object, e As DataGridPageChangedEventArgs)
MyDataGrid.CurrentPageIndex = e.NewPageIndex
BindGrid()
End Sub 'MyDataGrid_Page
Sub BindGrid()
MyDataGrid.DataSource = CreateDataSource()
MyDataGrid.DataBind()
ShowStats()
End Sub 'BindGrid
Sub ShowStats()
lblEnabled.Text = "AllowPaging is " & MyDataGrid.AllowPaging
lblCurrentIndex.Text = "CurrentPageIndex is " & MyDataGrid.CurrentPageIndex
lblPageCount.Text = "PageCount is " & MyDataGrid.PageCount
lblPageSize.Text = "PageSize is " & MyDataGrid.PageSize
End Sub 'ShowStats
</script>
<head runat="server">
<title>DataGrid Paging Example</title>
</head>
<body>
<h3>DataGrid Paging Example</h3>
<form id="form1" runat="server">
<asp:DataGrid id="MyDataGrid" runat="server"
AllowPaging="True"
PageSize="10"
OnPageIndexChanged="MyDataGrid_Page"
BorderColor="black"
BorderWidth="1"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
Font-Names="Verdana"
Font-Size="8pt">
<PagerStyle Mode="NumericPages"
HorizontalAlign="Right">
</PagerStyle>
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="#eeeeee">
</AlternatingItemStyle>
</asp:DataGrid>
<br />
<asp:Checkbox id="chk1" runat="server"
Text="Show numeric page navigation buttons"
Font-Names="Verdana"
Font-Size="8pt"
AutoPostBack="true"/>
<br />
<table style="background-color:#eeeeee; padding:6">
<tr>
<td style="display:inline">
<asp:Label id="lblEnabled"
runat="server"/><br />
<asp:Label id="lblCurrentIndex"
runat="server"/><br />
<asp:Label id="lblPageCount"
runat="server"/><br />
<asp:Label id="lblPageSize"
runat="server"/><br />
</td>
</tr>
</table>
</form>
</body>
</html>
<%@ 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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<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)));
// 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;
}
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 Selection_Change(Object sender, EventArgs e)
{
// Set the page size for the DataGrid control based on the
// user's selection.
ItemsGrid.PageSize =
Convert.ToInt32(PageSizeList.SelectedItem.Text);
// Rebind the data to refresh the DataGrid control.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
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>
<head runat="server">
<title>DataGrid PageSize Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid PageSize Example</h3>
Select the number of items to display on a page.
<br /><br />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
AutoGenerateColumns="False"
PageSize="10"
AllowPaging="True"
OnPageIndexChanged="Grid_Change"
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 />
<table cellpadding="5">
<tr>
<td>
<asp:Label id="Message"
Text="Page size:"
runat="server"
AssociatedControlID="PageSizeList"/>
</td>
</tr>
<tr>
<td>
<asp:DropDownList id="PageSizeList"
AutoPostBack="True"
OnSelectedIndexChanged="Selection_Change"
runat="server">
<asp:ListItem> 5 </asp:ListItem>
<asp:ListItem Selected="True"> 10 </asp:ListItem>
<asp:ListItem> 15 </asp:ListItem>
<asp:ListItem> 20 </asp:ListItem>
</asp:DropDownList>
</td>
</tr>
</table>
</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" >
<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(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 Selection_Change(sender As Object, e As EventArgs)
' Set the page size for the DataGrid control based on the
' user's selection.
ItemsGrid.PageSize = Convert.ToInt32(PageSizeList.SelectedItem.Text)
' Rebind the data to refresh the DataGrid control.
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End Sub
Sub Grid_Change(sender As Object, 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>
<head runat="server">
<title>DataGrid PageSize Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid PageSize Example</h3>
Select the number of items to display on a page.
<br /><br />
<b>Product List</b>
<asp:DataGrid id="ItemsGrid"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
AutoGenerateColumns="False"
PageSize="10"
AllowPaging="True"
OnPageIndexChanged="Grid_Change"
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 />
<table cellpadding="5">
<tr>
<td>
<asp:Label id="Message"
Text="Page size:"
runat="server"
AssociatedControlID="PageSizeList"/>
</td>
</tr>
<tr>
<td>
<asp:DropDownList id="PageSizeList"
AutoPostBack="True"
OnSelectedIndexChanged="Selection_Change"
runat="server">
<asp:ListItem> 5 </asp:ListItem>
<asp:ListItem Selected="True"> 10 </asp:ListItem>
<asp:ListItem> 15 </asp:ListItem>
<asp:ListItem> 20 </asp:ListItem>
</asp:DropDownList>
</td>
</tr>
</table>
</form>
</body>
</html>
Commenti
Utilizzare questa proprietà per specificare il numero di elementi da visualizzare in una singola pagina del DataGrid controllo. La AllowPaging proprietà deve essere impostata su true
per questa proprietà.
Si applica a
Vedi anche
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