DataGrid.AllowPaging Propriété

Définition

Obtient ou définit une valeur indiquant si la pagination est activée.

public:
 virtual property bool AllowPaging { bool get(); void set(bool value); };
public virtual bool AllowPaging { get; set; }
member this.AllowPaging : bool with get, set
Public Overridable Property AllowPaging As Boolean

Valeur de propriété

true si la pagination est activée ; sinon, false. La valeur par défaut est false.

Exemples

L’exemple de code suivant montre comment utiliser la propriété pour activer la AllowPaging pagination.

<%@ 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">
 
   DataTable Cart;
   DataView CartView;
 
   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("CurrencyValue", typeof(double)));
 
      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) 
   {
 
      if (!IsPostBack) 
      {
         // Need to load this data only once.
         ItemsGrid.DataSource = CreateDataSource();
         ItemsGrid.DataBind();
      }
 
      if (CheckBox1.Checked)
         ItemsGrid.PagerStyle.Mode = PagerMode.NumericPages;
      else
         ItemsGrid.PagerStyle.Mode = PagerMode.NextPrev;

   }
 
   void Grid_Change(Object sender, DataGridPageChangedEventArgs e) 
   {
 
      // Set CurrentPageIndex to the page the user clicked.
      ItemsGrid.CurrentPageIndex = e.NewPageIndex;

      // Rebind the data. 
      ItemsGrid.DataSource = CreateDataSource();
      ItemsGrid.DataBind();
      
   }
 
 
</script>
 
<head runat="server">
    <title>DataGrid Paging Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

   <h3>DataGrid Paging Example</h3>
 
   <asp:DataGrid id="ItemsGrid" runat="server"
        BorderColor="black"
        BorderWidth="1"
        CellPadding="3"
        AllowPaging="true"
        AutoGenerateColumns="false"        
        OnPageIndexChanged="Grid_Change">
 
      <HeaderStyle BackColor="#00aaaa">
      </HeaderStyle>
 
      <PagerStyle Mode="NextPrev">
      </PagerStyle> 

      <Columns>

         <asp:BoundColumn 
              HeaderText="Number" 
              DataField="IntegerValue"/>
 
        <asp:BoundColumn 
              HeaderText="Item" 
              DataField="StringValue"/>

         <asp:BoundColumn 
              HeaderText="Price" 
              DataField="CurrencyValue" 
              DataFormatString="{0:c}">
 
            <ItemStyle HorizontalAlign="right">
            </ItemStyle>
     
         </asp:BoundColumn>

      </Columns>

   </asp:DataGrid>

   <br />

   <asp:CheckBox id="CheckBox1" 
                 Text="Show page navigation"
                 AutoPostBack="true"
                 runat="server"/>
 
   </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">
 
        Dim Cart As DataTable
        Dim CartView As DAtaView

        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("CurrencyValue", GetType(Double)))
            
            Dim i As Integer
            For i = 0 To 99
                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 New DataView(dt)
            Return dv
        End Function 'CreateDataSource


        Sub Page_Load(sender As Object, e As EventArgs)
            
            If Not IsPostBack Then
                ' Need to load this data only once.
                ItemsGrid.DataSource = CreateDataSource()
                ItemsGrid.DataBind()
            End If
            
            If CheckBox1.Checked Then
                ItemsGrid.PagerStyle.Mode = PagerMode.NumericPages
            Else
                ItemsGrid.PagerStyle.Mode = PagerMode.NextPrev
            End If 
        End Sub 'Page_Load


        Sub Grid_Change(sender As Object, e As DataGridPageChangedEventArgs)
            
            ' Set CurrentPageIndex to the page the user clicked.
            ItemsGrid.CurrentPageIndex = e.NewPageIndex
            
            ' Rebind the data. 
            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()
        End Sub 'Grid_Change  
</script>
 
<head runat="server">
    <title>DataGrid Paging Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

   <h3>DataGrid Paging Example</h3>
 
   <asp:DataGrid id="ItemsGrid" runat="server"
        BorderColor="black"
        BorderWidth="1"
        CellPadding="3"
        AllowPaging="true"
        AutoGenerateColumns="false"        
        OnPageIndexChanged="Grid_Change">
 
      <HeaderStyle BackColor="#00aaaa">
      </HeaderStyle>
 
      <PagerStyle Mode="NextPrev">
      </PagerStyle> 

      <Columns>

         <asp:BoundColumn 
              HeaderText="Number" 
              DataField="IntegerValue"/>
 
        <asp:BoundColumn 
              HeaderText="Item" 
              DataField="StringValue"/>

         <asp:BoundColumn 
              HeaderText="Price" 
              DataField="CurrencyValue" 
              DataFormatString="{0:c}">
 
            <ItemStyle HorizontalAlign="right">
            </ItemStyle>
     
         </asp:BoundColumn>

      </Columns>

   </asp:DataGrid>

   <br />

   <asp:CheckBox id="CheckBox1" 
                 Text="Show page navigation"
                 AutoPostBack="true"
                 runat="server"/>
 
   </form>
 
</body>
</html>
<%@ 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>

Remarques

La pagination vous permet d’afficher le contenu du DataGrid contrôle dans des segments de page. Le nombre d’éléments d’une page est déterminé par la PageSize propriété . Si aucune valeur n’est spécifiée pour la PageSize propriété, le DataGrid contrôle affiche 10 éléments sur une page.

Par défaut, la pagination est désactivée. Pour activer la pagination, définissez cette propriété true sur et fournissez du code pour gérer l’événement PageIndexChanged .

La logique classique de l’événement PageIndexChanged consiste à définir la CurrentPageIndex propriété sur l’index de la page que vous souhaitez afficher, puis à utiliser la DataBind méthode pour lier les données au DataGrid contrôle.

Notes

Le gestionnaire d’événements reçoit un DataGridPageChangedEventArgs objet en tant que paramètre. Vous pouvez utiliser la NewPageIndex propriété de ce paramètre pour déterminer l’index de la page sélectionnée par l’utilisateur à partir des éléments de sélection de page du DataGrid contrôle.

Avec la pagination standard, le DataGrid contrôle suppose que la source de données contient tous les éléments à afficher. Le DataGrid contrôle calcule les index des éléments de la page affichée en fonction de l’index de page, spécifié par la CurrentPageIndex propriété, et du nombre d’éléments d’éléments d’une page, spécifié par la PageSize propriété .

Normalement, une source de données qui contient tous les éléments à afficher est chargée chaque fois que le DataGrid contrôle est paginé. Cela peut consommer beaucoup de ressources lorsque la source de données est très volumineuse. La pagination personnalisée vous permet de charger uniquement le segment de données nécessaire pour afficher une seule page. Pour plus d’informations sur la pagination personnalisée, consultez la AllowCustomPaging propriété .

S’applique à

Voir aussi