DataGrid.AllowPaging 属性

定义

获取或设置指示是否启用分页的值。Gets or sets a value that indicates whether paging is enabled.

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

属性值

Boolean

如果启用分页,则为 true;否则为 falsetrue if paging is enabled; otherwise, false. 默认值是 falseThe default value is false.

示例

下面的代码示例演示如何使用 AllowPaging 属性来启用分页。The following code example demonstrates how to use the AllowPaging property to enable paging.

<%@ 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>

注解

分页允许您 DataGrid 在页面段中显示控件的内容。Paging allows you to display the contents of the DataGrid control in page segments. 页面上的项数由 PageSize 属性确定。The number of items on a page is determined by the PageSize property. 如果没有为属性指定值 PageSize ,则 DataGrid 控件将在页面上显示10个项。If no value is specified for the PageSize property, the DataGrid control will display 10 items on a page.

默认情况下,分页处于禁用状态。By default, paging is disabled. 若要启用分页,请将此属性设置为 true ,并提供代码来处理 PageIndexChanged 事件。To enable paging, set this property to true and provide code to handle the PageIndexChanged event.

事件的典型逻辑 PageIndexChanged 是将 CurrentPageIndex 属性设置为要显示的页的索引,然后使用 DataBind 方法将数据绑定到 DataGrid 控件。The typical logic for the PageIndexChanged event is to set the CurrentPageIndex property to the index of the page you want to display and then use the DataBind method to bind the data to the DataGrid control.

备注

事件处理程序接收 DataGridPageChangedEventArgs 对象作为参数。The event handler receives a DataGridPageChangedEventArgs object as a parameter. 您可以使用 NewPageIndex 此参数的属性,以确定用户从控件的页选择元素中选择的页的索引 DataGridYou can use the NewPageIndex property of this parameter to determine the index of the page selected by the user from the page selection elements of the DataGrid control.

通过标准分页, DataGrid 控件假设数据源包含所有要显示的项。With standard paging, the DataGrid control assumes that the data source contains all the items to be displayed. DataGrid控件基于页索引、属性指定的页索引 CurrentPageIndex 和页上项的项数(由属性指定)来计算所显示页上项的索引 PageSizeThe DataGrid control calculates the indexes of the items on the displayed page based on the page index, specified by the CurrentPageIndex property, and the number of items of items on a page, specified by the PageSize property.

通常,每次对控件进行分页时,都将加载包含要显示的所有项的数据源 DataGridNormally, a data source that contains all items to be displayed is loaded every time the DataGrid control is paged. 当数据源非常大时,这可能会占用大量资源。This can consume a lot of resources when the data source is very large. 自定义分页允许只加载显示单个页面所需的数据段。Custom paging allows you to load just the segment of data needed to display a single page. 有关自定义分页的其他信息,请参见 AllowCustomPaging 属性。For additional information on custom paging, see the AllowCustomPaging property.

适用于

另请参阅