ListViewEditEventArgs 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 ItemEditing event.
public ref class ListViewEditEventArgs : System::ComponentModel::CancelEventArgspublic class ListViewEditEventArgs : System.ComponentModel.CancelEventArgstype ListViewEditEventArgs = class
inherit CancelEventArgsPublic Class ListViewEditEventArgs
Inherits CancelEventArgs- Inheritance
Examples
The following example shows how to use the ListViewEditEventArgs object to cancel the edit operation when the user tries to update a discontinued item.
Important
This example has 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>
void ProductsListView_ItemEditing(Object sender, ListViewEditEventArgs e)
{
ListViewItem item = ProductsListView.Items[e.NewEditIndex];
Label dateLabel = (Label)item.FindControl("DiscontinuedDateLabel");
if (String.IsNullOrEmpty(dateLabel.Text))
return;
//Verify if the item is discontinued.
DateTime discontinuedDate = DateTime.Parse(dateLabel.Text);
if (discontinuedDate < DateTime.Now)
{
Message.Text = "You cannot edit a discontinued item.";
e.Cancel = true;
ProductsListView.SelectedIndex = -1;
}
}
//</Snippet2>
void DiscontinuedDateCalendar_OnSelectionChanged(Object sender, EventArgs e)
{
TextBox dateTextBox =
(TextBox)ProductsListView.EditItem.FindControl("DiscontinuedDateTextBox");
Calendar calendarObject = (Calendar)sender;
dateTextBox.Text = calendarObject.SelectedDate.ToString("d");
}
DateTime GetDateTime(object dateValue)
{
if (dateValue == DBNull.Value)
return DateTime.Now;
else
return (DateTime)dateValue;
}
protected void ProductsListView_PagePropertiesChanging(object sender, PagePropertiesChangingEventArgs e)
{
// Clears the edit index selection when paging.
ProductsListView.EditIndex = -1;
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView Edit Item Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView Edit Item Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ProductsListView"
DataSourceID="ProductsDataSource"
DataKeyNames="ProductID"
OnItemEditing="ProductsListView_ItemEditing"
ConvertEmptyStringToNull="true"
OnPagePropertiesChanging="ProductsListView_PagePropertiesChanging"
runat="server" >
<LayoutTemplate>
<table cellpadding="2" runat="server" id="tblProducts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="ProductsDataPager" 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" />
</td>
<td valign="top">
<asp:Label ID="NameLabel" runat="server" Text='<%#Eval("Name") %>' />
</td>
<td valign="top">
<asp:Label ID="ProductNumberLabel" runat="server" Text='<%#Eval("ProductNumber") %>' />
</td>
<td>
<asp:Label ID="DiscontinuedDateLabel" runat="server"
Text='<%#Eval("DiscontinuedDate", "{0:d}") %>' />
</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="CancelButton" runat="server"
CommandName="Cancel" Text="Cancel" />
</td>
<td valign="top" colspan="2">
<asp:Label runat="server" ID="NameLabel"
AssociatedControlID="NameTextBox"
Text="Name"/>
<asp:TextBox ID="NameTextBox" runat="server"
Text='<%#Bind("Name") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="ProductNumberLabel"
AssociatedControlID="ProductNumberTextBox"
Text="Product Number" />
<asp:TextBox ID="ProductNumberTextBox" runat="server"
Text='<%#Bind("ProductNumber") %>' MaxLength="25" /><br />
</td>
<td>
<asp:Label runat="server" ID="DiscontinuedDateLabel"
AssociatedControlID="DiscontinuedDateTextBox"
Text="Discontinued Date"/>
<asp:TextBox ID="DiscontinuedDateTextBox" runat="server"
Text='<%# Bind("DiscontinuedDate", "{0:d}") %>'
MaxLength="10" /><br />
<asp:Calendar ID="DiscontinuedDateCalendar" runat="server"
SelectedDate='<%# GetDateTime(Eval("DiscontinuedDate")) %>'
OnSelectionChanged="DiscontinuedDateCalendar_OnSelectionChanged" />
</td>
</tr>
</EditItemTemplate>
</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="ProductsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ProductID], [Name], [ProductNumber], [DiscontinuedDate]
FROM Production.Product"
UpdateCommand="UPDATE Production.Product
SET Name = @Name, ProductNumber = @ProductNumber, DiscontinuedDate = @DiscontinuedDate
WHERE ProductID = @ProductID">
</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>
Sub ProductsListView_ItemEditing(ByVal sender As Object, ByVal e As ListViewEditEventArgs)
Dim item As ListViewItem = ProductsListView.Items(e.NewEditIndex)
Dim dateLabel As Label = CType(item.FindControl("DiscontinuedDateLabel"), Label)
If String.IsNullOrEmpty(dateLabel.Text) Then _
Return
'Verify if the item is discontinued.
Dim discontinuedDate As DateTime = DateTime.Parse(dateLabel.Text)
If discontinuedDate < DateTime.Now Then
Message.Text = "You cannot edit a discontinued item."
e.Cancel = True
ProductsListView.SelectedIndex = -1
End If
End Sub
'</Snippet2>
Sub DiscontinuedDateCalendar_OnSelectionChanged(ByVal sender As Object, ByVal e As EventArgs)
Dim dateTextBox As TextBox = _
CType(ProductsListView.EditItem.FindControl("DiscontinuedDateTextBox"), TextBox)
Dim calendarObject As Calendar = CType(sender, Calendar)
dateTextBox.Text = calendarObject.SelectedDate.ToString("d")
End Sub
Function GetDateTime(ByVal dateValue As Object) As DateTime
If dateValue Is DBNull.Value Then
Return DateTime.Now
Else
Return CType(dateValue, DateTime)
End If
End Function
Protected Sub ProductsListView_PagePropertiesChanging(ByVal sender As Object, _
ByVal e As PagePropertiesChangingEventArgs)
' Clears the edit index selection when paging.
ProductsListView.EditIndex = -1
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListView Edit Item Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListView Edit Item Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ProductsListView"
DataSourceID="ProductsDataSource"
DataKeyNames="ProductID"
OnItemEditing="ProductsListView_ItemEditing"
ConvertEmptyStringToNull="true"
OnPagePropertiesChanging="ProductsListView_PagePropertiesChanging"
runat="server" >
<LayoutTemplate>
<table cellpadding="2" runat="server" id="tblProducts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="ProductsDataPager" 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" />
</td>
<td valign="top">
<asp:Label ID="NameLabel" runat="server" Text='<%#Eval("Name") %>' />
</td>
<td valign="top">
<asp:Label ID="ProductNumberLabel" runat="server" Text='<%#Eval("ProductNumber") %>' />
</td>
<td>
<asp:Label ID="DiscontinuedDateLabel" runat="server"
Text='<%#Eval("DiscontinuedDate", "{0:d}") %>' />
</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="CancelButton" runat="server"
CommandName="Cancel" Text="Cancel" />
</td>
<td valign="top" colspan="2">
<asp:Label runat="server" ID="NameLabel"
AssociatedControlID="NameTextBox"
Text="Name"/>
<asp:TextBox ID="NameTextBox" runat="server"
Text='<%#Bind("Name") %>' MaxLength="50" /><br />
<asp:Label runat="server" ID="ProductNumberLabel"
AssociatedControlID="ProductNumberTextBox"
Text="Product Number" />
<asp:TextBox ID="ProductNumberTextBox" runat="server"
Text='<%#Bind("ProductNumber") %>' MaxLength="25" /><br />
</td>
<td>
<asp:Label runat="server" ID="DiscontinuedDateLabel"
AssociatedControlID="DiscontinuedDateTextBox"
Text="Discontinued Date"/>
<asp:TextBox ID="DiscontinuedDateTextBox" runat="server"
Text='<%# Bind("DiscontinuedDate", "{0:d}") %>'
MaxLength="10" /><br />
<asp:Calendar ID="DiscontinuedDateCalendar" runat="server"
SelectedDate='<%# GetDateTime(Eval("DiscontinuedDate")) %>'
OnSelectionChanged="DiscontinuedDateCalendar_OnSelectionChanged" />
</td>
</tr>
</EditItemTemplate>
</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="ProductsDataSource" runat="server"
ConnectionString="<%$ ConnectionStrings:AdventureWorks_DataConnectionString %>"
SelectCommand="SELECT [ProductID], [Name], [ProductNumber], [DiscontinuedDate]
FROM Production.Product"
UpdateCommand="UPDATE Production.Product
SET Name = @Name, ProductNumber = @ProductNumber, DiscontinuedDate = @DiscontinuedDate
WHERE ProductID = @ProductID">
</asp:SqlDataSource>
</form>
</body>
</html>
Remarks
The ListView control raises the ItemEditing event when an Edit button is clicked, but before the ListView item enters edit mode. (An Edit button is a button whose CommandName property set to "Edit".) This enables you to provide an event-handling method that performs a custom routine whenever this event occurs, such as canceling the edit operation.
A ListViewEditEventArgs object is passed to the event-handling method. This object enables you to determine the index of the item that is being edited, and to indicate that the edit operation should be canceled. To cancel the edit operation, set the Cancel property of the ListViewEditEventArgs object to true.
For a list of initial property values for an instance of ListViewEditEventArgs, see the ListViewEditEventArgs constructor.
Constructors
| ListViewEditEventArgs(Int32) |
Initializes a new instance of the ListViewEditEventArgs class. |
Properties
| Cancel |
Gets or sets a value indicating whether the event should be canceled. (Inherited from CancelEventArgs) |
| NewEditIndex |
Gets the index of the item that is being edited. |
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
Met ons samenwerken op GitHub
De bron voor deze inhoud vindt u op GitHub, waar u ook problemen en pull-aanvragen kunt maken en controleren. Bekijk onze gids voor inzenders voor meer informatie.
