ListViewCancelEventArgs Class
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Provides data for the ItemCanceling event.
public ref class ListViewCancelEventArgs : System::ComponentModel::CancelEventArgspublic class ListViewCancelEventArgs : System.ComponentModel.CancelEventArgstype ListViewCancelEventArgs = class
inherit CancelEventArgsPublic Class ListViewCancelEventArgs
Inherits CancelEventArgs- Inheritance
Examples
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.
Important
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;
}
// <Snippet2>
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.";
}
}
// </Snippet2>
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">Email 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>
<%@ 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()
Message.Text = String.Empty
End Sub
' <Snippet2>
Protected Sub ContactsListView_ItemCanceling(ByVal sender As Object, _
ByVal e As ListViewCancelEventArgs)
'Check the operation that raised the event
If (e.CancelMode = ListViewCancelMode.CancelingEdit) Then
' 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."
End If
End Sub
' </Snippet2>
Protected Sub ContactsListView_PagePropertiesChanging(ByVal sender As Object, _
ByVal e As PagePropertiesChangingEventArgs)
' Clears the edit index selection when paging.
ContactsListView.EditIndex = -1
End Sub
</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">Email 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>
Remarks
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.
Constructors
| ListViewCancelEventArgs(Int32, ListViewCancelMode) |
Initializes a new instance of the ListViewCancelEventArgs class. |
Properties
| Cancel |
Gets or sets a value indicating whether the event should be canceled. (Inherited from CancelEventArgs) |
| CancelMode |
Gets the data-entry mode that the ListView control was in when the Cancel button was clicked. |
| ItemIndex |
Gets the index of the item that contains the Cancel button that raised the event. |
Methods
| Equals(Object) |
Determines whether the specified object is equal to the current object. (Inherited from Object) |
| GetHashCode() |
Serves as the default hash function. (Inherited from Object) |
| GetType() |
Gets the Type of the current instance. (Inherited from Object) |
| MemberwiseClone() |
Creates a shallow copy of the current Object. (Inherited from Object) |
| ToString() |
Returns a string that represents the current object. (Inherited from Object) |
Applies to
See also
Werk met ons samen op GitHub
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