FormView.ItemDeleted FormView.ItemDeleted FormView.ItemDeleted FormView.ItemDeleted Event

Definizione

Si verifica quando viene fatto clic su un pulsante Elimina in un controllo FormView, ma dopo l'operazione di eliminazione.Occurs when a Delete button within a FormView control is clicked, but after the delete operation.

public:
 event System::Web::UI::WebControls::FormViewDeletedEventHandler ^ ItemDeleted;
public event System.Web.UI.WebControls.FormViewDeletedEventHandler ItemDeleted;
member this.ItemDeleted : System.Web.UI.WebControls.FormViewDeletedEventHandler 
Public Custom Event ItemDeleted As FormViewDeletedEventHandler 

Esempi

Nell'esempio seguente viene illustrato come utilizzare l' ItemDeleted evento per determinare se si è verificata un'eccezione durante un'operazione di eliminazione.The following example demonstrates how to use the ItemDeleted event to determine whether an exception occurred during a delete operation.


<%@ 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 EmployeeFormView_ItemDeleted(Object sender, FormViewDeletedEventArgs e)
  {
    // Use the Exception property to determine whether an exception
    // occurred during the delete operation.
    if (e.Exception == null)
    {
      // Use the AffectedRows property to determine whether the
      // record was deleted. Sometimes an error might occur that 
      // does not raise an exception, but prevents the delete
      // operation from completing.
      if (e.AffectedRows == 1)
      {
        MessageLabel.Text = "Record deleted successfully.";
      }
      else
      {
        MessageLabel.Text = "An error occurred during the delete operation.";
      }
    }
    else
    {
      // Insert the code to handle the exception.
      MessageLabel.Text = e.Exception.Message;
      
      // Use the ExceptionHandled property to indicate that the 
      // exception has already been handled.
      e.ExceptionHandled = true;
    }
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewDeletedEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewDeletedEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        onitemdeleted="EmployeeFormView_ItemDeleted"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td>
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td>
                <h3><%# Eval("FirstName") %>&nbsp;<%# Eval("LastName") %></h3>      
                <%# Eval("Title") %>        
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="DeleteButton"
                  text="Delete Record"
                  commandname="Delete"
                  runat="server" />
              </td>
            </tr>
          </table>
        
        </itemtemplate>         
                  
      </asp:formview>
      
      <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="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </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 EmployeeFormView_ItemDeleted(ByVal sender As Object, ByVal e As FormViewDeletedEventArgs) Handles EmployeeFormView.ItemDeleted
  
    ' Use the Exception property to determine whether an exception
    ' occurred during the delete operation.
    If e.Exception Is Nothing Then
    
      ' Use the AffectedRows property to determine whether the
      ' record was deleted. Sometimes an error might occur that 
      ' does not raise an exception, but prevents the delete
      ' operation from completing.
      If e.AffectedRows = 1 Then
      
        MessageLabel.Text = "Record deleted successfully."
      
      Else
              
        MessageLabel.Text = "An error occurred during the delete operation."
      
      End If
    
    Else
    
      ' Insert the code to handle the exception.
      MessageLabel.Text = e.Exception.Message
      
      ' Use the ExceptionHandled property to indicate that the 
      ' exception has already been handled.
      e.ExceptionHandled = True
      
    End If
    
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewDeletedEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewDeletedEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td>
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td>
                <h3><%# Eval("FirstName") %>&nbsp;<%# Eval("LastName") %></h3>      
                <%# Eval("Title") %>        
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="DeleteButton"
                  text="Delete Record"
                  commandname="Delete"
                  runat="server" />
              </td>
            </tr>
          </table>
        
        </itemtemplate>         
                  
      </asp:formview>
      
      <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="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

Commenti

Il FormView controllo genera l' ItemDeleted evento quando viene fatto clic su un pulsante Elimina ( CommandName un pulsante con la relativa proprietà impostata su "Delete") all'interno del controllo, FormView ma dopo che il controllo ha eliminato il record.The FormView control raises the ItemDeleted event when a Delete button (a button with its CommandName property set to "Delete") within the control is clicked, but after the FormView control deletes the record. Questo consente di fornire un metodo di gestione degli eventi che esegue una routine personalizzata, ad esempio il controllo dei risultati di un'operazione di eliminazione, ogni volta che si verifica questo evento.This allows you to provide an event-handling method that performs a custom routine, such as checking the results of a delete operation, whenever this event occurs.

Un FormViewDeletedEventArgs oggetto viene passato al metodo di gestione degli eventi, che consente di determinare il numero di record interessati ed eventuali eccezioni che potrebbero essersi verificate.A FormViewDeletedEventArgs object is passed to the event-handling method, which allows you to determine the number of records affected and any exceptions that might have occurred. Per determinare il numero di record interessati dall'operazione di eliminazione, utilizzare la AffectedRows proprietà.To determine the number of records affected by the delete operation, use the AffectedRows property. Utilizzare la Exception proprietà per determinare se si sono verificate eccezioni.Use the Exception property to determine whether any exceptions occurred. È inoltre possibile indicare se l'eccezione è stata gestita nel metodo di gestione degli eventi impostando ExceptionHandled la proprietà.You can also indicate whether the exception was handled in the event-handling method by setting the ExceptionHandled property. Se si desidera accedere alle coppie nome/valore dei campi chiave e dei campi non chiave del record eliminato, utilizzare rispettivamente le Keys proprietà e. ValuesIf you want to access the name/value pairs of the key fields and non-key fields of the deleted record, use the Keys and Values properties, respectively.

Per altre informazioni su come gestire gli eventi, vedere la gestione e generazione di eventi.For more information about how to handle events, see Handling and Raising Events.

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