DataGrid.OnPageIndexChanged Method
Raises the PageIndexChanged event. This allows you to provide a custom handler for the event.
[Visual Basic] Protected Overridable Sub OnPageIndexChanged( _ ByVal e As DataGridPageChangedEventArgs _ ) [C#] protected virtual void OnPageIndexChanged( DataGridPageChangedEventArgs e ); [C++] protected: virtual void OnPageIndexChanged( DataGridPageChangedEventArgs* e ); [JScript] protected function OnPageIndexChanged( e : DataGridPageChangedEventArgs );
Parameters
- e
- A DataGridPageChangedEventArgs that contains event data.
Remarks
Use the OnPageIndexChanged method to provide a custom handler for the PageIndexChanged event.
The PageIndexChanged event is raised when one of the page selection elements is clicked.
A typical handler for the PageIndexChanged event sets the CurrentPageIndex property to the index of the page you want to display and then uses the DataBind method to bind the data to the DataGrid control.
Note The event handler receives a DataGridPageChangedEventArgs object as a parameter. You 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.
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
Notes to Inheritors: When overriding OnPageIndexChanged in a derived class, be sure to call the base class's OnPageIndexChanged method.
For more information about handling events, see Consuming Events.
Example
[Visual Basic, C#] The following example demonstrates how to specify and code a handler for the PageIndexChanged event. It displays pages on the DataGrid control in 10-item increments.
[Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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 Check_Change(sender As Object, e As EventArgs) ' Allow or prevent paging depending on the user's selection. If AllowPagingCheckBox.Checked Then ItemsGrid.AllowPaging = True Else ItemsGrid.AllowPaging = False End If ' 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> <body> <form runat=server> <h3>DataGrid AllowPaging 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" 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:CheckBox id="AllowPagingCheckBox" Text="Allow paging" AutoPostBack="True" Checked="True" OnCheckedChanged="Check_Change" runat="server"/> </td> </tr> </table> </form> </body> </html> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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 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; } // 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> <body> <form runat=server> <h3>DataGrid AllowPaging 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" 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:CheckBox id="AllowPagingCheckBox" Text="Allow paging" AutoPostBack="True" Checked="True" OnCheckedChanged="Check_Change" runat="server"/> </td> </tr> </table> </form> </body> </html> [Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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 ' Manually register the event-handling method for the PageIndexChanged ' event of the DataGrid control. AddHandler ItemsGrid.PageIndexChanged, AddressOf Grid_Change End Sub Sub Check_Change(sender As Object, e As EventArgs) ' Allow or prevent paging depending on the user's selection. If AllowPagingCheckBox.Checked Then ItemsGrid.AllowPaging = True Else ItemsGrid.AllowPaging = False End If ' Re-bind 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 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() End Sub </script> <body> <form 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> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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> <body> <form 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>
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Requirements
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
See Also
DataGrid Class | DataGrid Members | System.Web.UI.WebControls Namespace | PageIndexChanged | DataGridPageChangedEventArgs | DataGridPageChangedEventHandler