DataGridPageChangedEventHandler 委托

定义

表示处理 PageIndexChanged 控件的 DataGrid 事件的方法。

C#
public delegate void DataGridPageChangedEventHandler(object source, DataGridPageChangedEventArgs e);

参数

source
Object

事件源。

示例

下面的代码示例演示如何为 PageIndexChanged 事件指定处理程序并为其编写代码。 它以 10 项为增量显示控件上的 DataGrid 页面。

ASP.NET (C#)
<%@ 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>
ASP.NET (C#)

<%@ 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();
         
         }

         // Manually register the event-handling method for the PageIndexChanged  
         // event of the DataGrid control.
         ItemsGrid.PageIndexChanged += new DataGridPageChangedEventHandler(this.Grid_Change);

      }

      void Check_Change(Object sender, EventArgs e)
      {
   
         // Allow or prevent paging depending on the user's selection.
         if (AllowPagingCheckBox.Checked)
         {

            ItemsGrid.AllowPaging = true;

         }
         else
         {

            ItemsGrid.AllowPaging = false;

         }

         // Re-bind 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 programmatically updated.
         // 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;

         // Re-bind the data to refresh the DataGrid control. 
         ItemsGrid.DataSource = CreateDataSource();
         ItemsGrid.DataBind();
      
      }

   </script>
 
<head runat="server">
    <title>DataGrid PageIndexChanged Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGrid PageIndexChanged Example</h3>

      Select whether to allow paging in the DataGrid control.

      <br /><br />
 
      <b>Product List</b>
 
      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           AutoGenerateColumns="False"
           PageSize="10"
           AllowPaging="True"
           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:CheckBox id="AllowPagingCheckBox"
                    Text="Allow paging"
                    AutoPostBack="True"
                    Checked="True"
                    OnCheckedChanged="Check_Change"
                    runat="server"/>

            </td>
            
         </tr>

      </table>
 
   </form>
 
</body>
</html>

注解

单击 PageIndexChanged 控件的页面选择元素 DataGrid 中的按钮时,将引发 事件。

创建 DataGridPageChangedEventHandler 委托时,需要标识将处理该事件的方法。 若要将事件与事件处理程序关联,请将该委托的一个实例添加到事件中。 除非移除了该委托,否则每当发生该事件时就会调用事件处理程序。 有关事件处理程序委托的详细信息,请参阅 处理和引发事件

扩展方法

GetMethodInfo(Delegate)

获取指示指定委托表示的方法的对象。

适用于

产品 版本
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

另请参阅