ListViewCancelEventArgs Class
Provides data for the ItemCanceling event.
Assembly: System.Web.Extensions (in System.Web.Extensions.dll)
The ListView control raises the ItemCanceling event when the Cancel button is clicked, but before exiting insert or edit mode. (A Cancel button is a button whose CommandName property is set to "Cancel") This enables you to provide an event-handling method that performs a custom routine whenever this event occurs, such as stopping the cancel operation if it would put the item in an unwanted state.
A ListViewCancelEventArgs object is passed to the event-handling method. This object enables you to determine the index of the item that contains the Cancel button that raised the event. You can also determine what operation was canceled. To stop the cancel operation, set the Cancel property to true.
For a list of initial property values for an instance of the ListViewCancelEventArgs class, see the ListViewCancelEventArgs constructor.
The following example shows how to use the ListViewCancelEventArgs object to display a message when the user cancels the insert or update operation in a ListView control. The ListViewCancelEventArgs object is passed to the event-handling method for the ItemCanceling event.
Security Note: |
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This example contains a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview. |
<%@ Page language="C#" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> void Page_Load() { Message.Text = String.Empty; } protected void ContactsListView_ItemCanceling(object sender, ListViewCancelEventArgs e) { //Check the operation that raised the event if (e.CancelMode == ListViewCancelMode.CancelingEdit) { // The update operation was canceled. Display the // primary key of the item. Message.Text = "Update for the ContactID " + ContactsListView.DataKeys[e.ItemIndex].Value.ToString() + " canceled."; } else { Message.Text = "Insert operation canceled."; } } protected void ContactsListView_PagePropertiesChanging(object sender, PagePropertiesChangingEventArgs e) { // Clears the edit index selection when paging. ContactsListView.EditIndex = -1; } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head1" runat="server"> <title>ListView ItemCanceling Example</title> </head> <body> <form id="form1" runat="server"> <h3>ListView ItemCanceling Example</h3> <asp:Label ID="Message" ForeColor="Red" runat="server"/> <br/> <asp:ListView ID="ContactsListView" DataSourceID="ContactsDataSource" DataKeyNames="ContactID" ConvertEmptyStringToNull="true" InsertItemPosition="LastItem" runat="server" OnItemCanceling="ContactsListView_ItemCanceling" OnPagePropertiesChanging="ContactsListView_PagePropertiesChanging" > <LayoutTemplate> <table cellpadding="2" width="680px" border="1" runat="server" id="tblContacts"> <tr runat="server"> <th runat="server"> </th> <th runat="server">ID</th> <th runat="server">First Name</th> <th runat="server">Last Name</th> <th runat="server">E-mail Address</th> </tr> <tr runat="server" id="itemPlaceholder" /> </table> <asp:DataPager runat="server" ID="ContactsDataPager" PageSize="12"> <Fields> <asp:NextPreviousPagerField ShowFirstPageButton="true" ShowLastPageButton="true" FirstPageText="|<< " LastPageText=" >>|" NextPageText=" > " PreviousPageText=" < " /> </Fields> </asp:DataPager> </LayoutTemplate> <ItemTemplate> <tr runat="server"> <td valign="top"> <asp:LinkButton ID="EditButton" runat="server" Text="Edit" CommandName="Edit" /><br /> </td> <td valign="top"> <asp:Label ID="Label1" runat="server" Text='<%#Eval("ContactID") %>' /> </td> <td valign="top"> <asp:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' /> </td> <td valign="top"> <asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' /> </td> <td valign="top"> <asp:Label ID="EmailAddressLabel" runat="server" Text='<%#Eval("EmailAddress") %>' /> </td> </tr> </ItemTemplate> <EditItemTemplate> <tr style="background-color: #ADD8E6"> <td valign="top"> <asp:LinkButton ID="UpdateButton" runat="server" CommandName="Update" Text="Update" /><br /> <asp:LinkButton ID="CancelEditButton" runat="server" CommandName="Cancel" Text="Cancel" /> </td> <td> <asp:Label ID="Label1" runat="server" Text='<%#Eval("ContactID") %>' /> </td> <td> <asp:TextBox ID="FirstNameTextBox" runat="server" Text='<%#Bind("FirstName") %>' MaxLength="50" /><br /> </td> <td> <asp:TextBox ID="LastNameTextBox" runat="server" Text='<%#Bind("LastName") %>' MaxLength="50" /><br /> </td> <td> <asp:TextBox ID="EmailAddressTextBox" runat="server" Text='<%#Bind("EmailAddress") %>' MaxLength="50" /><br /> </td> </tr> </EditItemTemplate> <InsertItemTemplate> <tr style="background-color:#90EE90"> <td colspan="2"> <asp:LinkButton ID="InsertButton" runat="server" CommandName="Insert" Text="Insert" /><br /> <asp:LinkButton ID="CancelInsertButton" runat="server" CommandName="Cancel" Text="Cancel" /> </td> <td> <asp:TextBox ID="FirstNameITextBox" runat="server" Text='<%#Bind("FirstName") %>' MaxLength="50" /> </td> <td> <asp:TextBox ID="LastNameITextBox" runat="server" Text='<%#Bind("LastName") %>' MaxLength="50" /> </td> <td> <asp:TextBox ID="EmailAddressITextBox" runat="server" Text='<%#Bind("EmailAddress") %>' MaxLength="50" /> </td> </tr> </InsertItemTemplate> </asp:ListView> <!-- This example uses Microsoft SQL Server and connects --> <!-- to the AdventureWorks sample database. Use an ASP.NET --> <!-- expression to retrieve the connection string value --> <!-- from the Web.config file. --> <asp:SqlDataSource ID="ContactsDataSource" runat="server" ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>" SelectCommand="SELECT [ContactID], [FirstName], [LastName], [EmailAddress] FROM Person.Contact" InsertCommand="INSERT INTO Person.Contact ([FirstName], [LastName], [EmailAddress], [PasswordHash], [PasswordSalt]) Values(@FirstName, @LastName, @EmailAddress, '', '')" UpdateCommand="UPDATE Person.Contact SET FirstName = @FirstName, LastName = @LastName, EmailAddress = @EmailAddress WHERE ContactID = @ContactID"> </asp:SqlDataSource> </form> </body> </html>
- AspNetHostingPermission
For operating in a hosted environment. Demand value: LinkDemand; Permission value: Minimal.
- AspNetHostingPermission
For operating in a hosted environment. Demand value: InheritanceDemand; Permission value: Minimal.
System.EventArgs
System.ComponentModel.CancelEventArgs
System.Web.UI.WebControls.ListViewCancelEventArgs
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Security Note: