DetailsViewPageEventHandler Delegate
Represents the method that handles the PageIndexChanging event of a DetailsView control.
Assembly: System.Web (in System.Web.dll)
Public Delegate Sub DetailsViewPageEventHandler ( sender As Object, e As DetailsViewPageEventArgs )
Parameters
- sender
-
Type:
System.Object
The source of the event.
- e
-
Type:
System.Web.UI.WebControls.DetailsViewPageEventArgs
A DetailsViewPageEventArgs that contains the event data.
The DetailsView control raises the PageIndexChanging event when a pager button (a button with its CommandName property set to "Page") within the control is clicked, but before the DetailsView control handles the paging operation. This allows you to provide an event handler that performs a custom routine, such as canceling the paging operation, whenever this event occurs.
Note |
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Pager buttons are usually located in the pager row of a DetailsView control. |
When you create a DetailsViewPageEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see NIB: Events and Delegates.
The following code example demonstrates how to programmatically add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.
<%@ Page language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) ' Create a new DetailsView object. Dim customerDetailsView As New DetailsView() ' Set the DetailsView object's properties. customerDetailsView.ID = "CustomerDetailsView" customerDetailsView.DataSourceID = "DetailsViewSource" customerDetailsView.AutoGenerateRows = True customerDetailsView.AutoGenerateEditButton = True customerDetailsView.AllowPaging = true customerDetailsView.PagerSettings.Position = PagerPosition.Bottom Dim keyArray() As String = {"CustomerID"} customerDetailsView.DataKeyNames = keyArray ' Programmatically register the event-handling methods ' for the DetailsView control. AddHandler customerDetailsView.PageIndexChanging, AddressOf CustomerDetailsView_PageIndexChanging AddHandler customerDetailsView.ModeChanging, AddressOf CustomerDetailsView_ModeChanging ' Add the DetailsView object to the Controls collection ' of the PlaceHolder control. DetailsViewPlaceHolder.Controls.Add(customerDetailsView) End Sub Sub CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs) ' Use the sender parameter to access the DetailsView control ' that raised the event. Dim customerDetailsView As DetailsView = CType(sender, DetailsView) ' Cancel the paging operation if the DetailsView control ' in edit mode. If customerDetailsView.CurrentMode = DetailsViewMode.Edit Then e.Cancel = True ' Display an error message. Dim newPage As Integer = e.NewPageIndex + 1 MessageLabel.Text = "Please update the current record before to moving to page " & _ newPage.ToString() & "." End If End Sub Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) ' Clear the message label when the user changes mode. MessageLabel.Text = "" End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>DetailsViewPageEventHandler Example</title> </head> <body> <form id="form1" runat="server"> <h3>DetailsViewPageEventHandler Example</h3> <!-- Use a PlaceHolder control as the container for the --> <!-- dynamically generated DetailsView control. --> <asp:placeholder id="DetailsViewPlaceHolder" runat="server"/> <br/><br/> <asp:label id="MessageLabel" forecolor="Red" runat="server"/> <!-- This example uses Microsoft SQL Server and connects --> <!-- to the Northwind sample database. Use an ASP.NET --> <!-- expression to retrieve the connection string value --> <!-- from the web.config file. --> <asp:sqldatasource id="DetailsViewSource" selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]" updatecommand="Update [Customers] Set [CompanyName]=@CompanyName, [Address]=@Address, [City]=@City, [PostalCode]=@PostalCode, [Country]=@Country Where [CustomerID]=@CustomerID" connectionstring= "<%$ ConnectionStrings:NorthWindConnectionString%>" runat="server"/> </form> </body> </html>
The following code example demonstrates how to declaratively add a DetailsViewPageEventHandler delegate to the PageIndexChanging event of a DetailsView control.
<%@ Page language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Sub CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs) Handles CustomerDetailsView.PageIndexChanging ' Cancel the paging operation if the DetailsView control ' in edit mode. If CustomerDetailsView.CurrentMode = DetailsViewMode.Edit Then e.Cancel = True ' Display an error message. Dim newPage As Integer = e.NewPageIndex + 1 MessageLabel.Text = "Please update the current record before to moving to page " & _ newPage.ToString() & "." End If End Sub Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging ' Clear the message label when the user changes mode. MessageLabel.Text = "" End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head runat="server"> <title>DetailsViewPageEventHandler Example</title> </head> <body> <form id="form1" runat="server"> <h3>DetailsViewPageEventHandler Example</h3> <asp:detailsview id="CustomerDetailsView" datasourceid="DetailsViewSource" autogeneraterows="true" autogenerateeditbutton="true" datakeynames="CustomerID" allowpaging="true" runat="server"> <pagersettings position="Bottom"/> </asp:detailsview> <br/> <asp:label id="MessageLabel" forecolor="Red" runat="server"/> <!-- This example uses Microsoft SQL Server and connects --> <!-- to the Northwind sample database. Use an ASP.NET --> <!-- expression to retrieve the connection string value --> <!-- from the web.config file. --> <asp:sqldatasource id="DetailsViewSource" selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]" updatecommand="Update [Customers] Set [CompanyName]=@CompanyName, [Address]=@Address, [City]=@City, [PostalCode]=@PostalCode, [Country]=@Country Where [CustomerID]=@CustomerID" connectionstring= "<%$ ConnectionStrings:NorthWindConnectionString%>" runat="server"/> </form> </body> </html>
Available since 2.0
