ListViewDeletedEventArgs.ExceptionHandled Propiedad
Definición
Importante
Parte de la información hace referencia a la versión preliminar del producto, que puede haberse modificado sustancialmente antes de lanzar la versión definitiva. Microsoft no otorga ninguna garantía, explícita o implícita, con respecto a la información proporcionada aquí.
Obtiene o establece un valor que indica si el control de una excepción provocada durante la operación de eliminación se ha realizado en el controlador de eventos.
public:
property bool ExceptionHandled { bool get(); void set(bool value); };public bool ExceptionHandled { get; set; }member this.ExceptionHandled : bool with get, setPublic Property ExceptionHandled As BooleanValor de propiedad
Es true si la excepción se ha controlado en el controlador de eventos; en caso contrario, es false. El valor predeterminado es false.
Ejemplos
En el ejemplo siguiente se muestra cómo usar la ExceptionHandled propiedad para indicar que la excepción se controló en el controlador de eventos.
<%@ 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;
}
void ContactsListView_ItemDeleted(Object sender, ListViewDeletedEventArgs e)
{
// Determine whether an exception occurred during the delete operation.
if (e.Exception == null)
{
// Ensure that a record was deleted.
if (e.AffectedRows > 0)
{
Message.Text = e.AffectedRows + " item(s) deleted successfully.";
}
else
{
Message.Text = "No item was deleted.";
}
}
else
{
// Insert the code to handle the exception here.
// Indicate that the exception has been handled.
e.ExceptionHandled = true;
Message.Text = "An error occurred during the delete operation.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ListViewDeletedEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListViewDeletedEventArgs Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnItemDeleted="ContactsListView_ItemDeleted"
runat="server">
<LayoutTemplate>
<table cellpadding="2" runat="server" id="tblContacts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" 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:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
<td>
<asp:LinkButton ID="DeleteButton" runat="server"
CommandName="Delete"
Text="Delete"
OnClientClick="return confirm('Are you sure?');" />
</td>
</tr>
</ItemTemplate>
</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"
DeleteCommand="DELETE FROM Person.Contact WHERE [ContactID] = @ContactID">
<DeleteParameters>
<asp:Parameter Name="ContactID" Type="Int32" />
</DeleteParameters>
</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
Sub ContactsListView_ItemDeleted(sender As Object, e As ListViewDeletedEventArgs)
' Determine whether an exception occurred during the delete operation.
If e.Exception Is Nothing Then
' Ensure that a record was deleted.
If e.AffectedRows > 0 Then
Message.Text = e.AffectedRows.ToString() & _
" item(s) deleted successfully."
Else
Message.Text = "No item was deleted."
End If
Else
' Insert the code to handle the exception here.
' Indicate that the exception has been handled.
e.ExceptionHandled = true
Message.Text = "An error occurred during the delete operation."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>ListViewDeletedEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>ListViewDeletedEventArgs Example</h3>
<asp:Label ID="Message"
ForeColor="Red"
runat="server"/>
<br/>
<asp:ListView ID="ContactsListView"
DataSourceID="ContactsDataSource"
DataKeyNames="ContactID"
OnItemDeleted="ContactsListView_ItemDeleted"
runat="server">
<LayoutTemplate>
<table cellpadding="2" runat="server" id="tblContacts" width="640px">
<tr runat="server" id="itemPlaceholder" />
</table>
<asp:DataPager runat="server" ID="PeopleDataPager" 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:Label ID="FirstNameLabel" runat="server" Text='<%#Eval("FirstName") %>' />
<asp:Label ID="LastNameLabel" runat="server" Text='<%#Eval("LastName") %>' />
</td>
<td>
<asp:Label ID="EmailLabel" runat="server" Text='<%#Eval("EmailAddress") %>' />
</td>
<td>
<asp:LinkButton ID="DeleteButton" runat="server"
CommandName="Delete"
Text="Delete"
OnClientClick="return confirm('Are you sure?');" />
</td>
</tr>
</ItemTemplate>
</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"
DeleteCommand="DELETE FROM Person.Contact WHERE [ContactID] = @ContactID">
<DeleteParameters>
<asp:Parameter Name="ContactID" Type="Int32" />
</DeleteParameters>
</asp:SqlDataSource>
</form>
</body>
</html>
Comentarios
Cuando se produce una excepción durante la operación de eliminación, use la ExceptionHandled propiedad para indicar si controló la excepción durante el evento. Si esta propiedad se establece trueen , la excepción se considera controlada y no se produce de nuevo. Si esta propiedad se establece en , el ListView control vuelve a falseproducir la excepción. Para determinar qué excepción se ha generado, use la Exception propiedad .