DetailsViewDeletedEventHandler Delegate

Definition

Rappresenta il metodo che gestisce l'evento ItemDeleted di un controllo DetailsView.Represents the method that handles the ItemDeleted event of a DetailsView control.

public delegate void DetailsViewDeletedEventHandler(System::Object ^ sender, DetailsViewDeletedEventArgs ^ e);
public delegate void DetailsViewDeletedEventHandler(object sender, DetailsViewDeletedEventArgs e);
type DetailsViewDeletedEventHandler = delegate of obj * DetailsViewDeletedEventArgs -> unit
Public Delegate Sub DetailsViewDeletedEventHandler(sender As Object, e As DetailsViewDeletedEventArgs)

Parameters

sender
Object

Origine dell'evento.The source of the event.

e
DetailsViewDeletedEventArgs

Elemento DetailsViewDeletedEventArgs contenente i dati dell'evento.A DetailsViewDeletedEventArgs that contains the event data.

Inheritance
DetailsViewDeletedEventHandler

Examples

Nell'esempio di codice seguente viene illustrato come aggiungere a livello di codice un delegato DetailsViewDeletedEventHandler all'evento ItemDeleted di un controllo DetailsView.The following code example demonstrates how to programmatically add a DetailsViewDeletedEventHandler delegate to the ItemDeleted event of a DetailsView control.


<%@ page language="C#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  
  <script runat="server">
  
    void Page_Load(Object sender, EventArgs e)
    {
      
      // Create a new DetailsView object.
      DetailsView customerDetailsView = new DetailsView();
      
      // Set the DetailsView object's properties.
      customerDetailsView.ID = "CustomerDetailsView";
      customerDetailsView.DataSourceID = "DetailsViewSource";
      customerDetailsView.AutoGenerateRows = true;
      customerDetailsView.AutoGenerateDeleteButton = true;
      customerDetailsView.AllowPaging = true;
      customerDetailsView.PagerSettings.Mode = 
        PagerButtons.NextPrevious;
      customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };

      // Programmatically register the event-handling method
      // for the ItemDeleted event of a DetailsView control.
      customerDetailsView.ItemDeleted += 
        new DetailsViewDeletedEventHandler(
        this.CustomerDetailView_ItemDeleted);

      // Add the DetailsView object to the Controls collection
      // of the PlaceHolder control.
      DetailsViewPlaceHolder.Controls.Add(customerDetailsView);

    }

    void CustomerDetailView_ItemDeleted(Object sender, 
      DetailsViewDeletedEventArgs 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 the numbers of
        // rows affected by the delete operation.
        if (e.AffectedRows == 1)
        {
          MessageLabel.Text = e.AffectedRows.ToString() 
            + " record deleted successfully.";
        }
        else
        {
          MessageLabel.Text = e.AffectedRows.ToString() 
            + " records deleted successfully.";
        }
      }
      else
      {
        // Insert the code to handle the exception.
        MessageLabel.Text = e.Exception.Message;

        // Use the ExceptionHandled property to indicate that the 
        // exception is already handled.
        e.ExceptionHandled = true;
      }
    }
  
  </script>
    
  <head runat="server">
    <title>DetailsViewDeletedEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeletedEventHandler Example</h3>
        
        <!-- Use a PlaceHolder control as the container for the -->
        <!-- dynamically generated DetailsView control.         -->       
        <asp:PlaceHolder id="DetailsViewPlaceHolder"
          runat="server"/>
          
        <br/><br/>
        
        <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="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          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">
<html xmlns="http://www.w3.org/1999/xhtml" >
  
  <script runat="server">
  
    Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
      
      ' Create a new DetailsView object.
      Dim customerDetailsView As New DetailsView()
      
      ' Set the DetailsView object's properties.
      customerDetailsView.ID = "CustomerDetailsView"
      customerDetailsView.DataSourceID = "DetailsViewSource"
      customerDetailsView.AutoGenerateRows = True
      customerDetailsView.AutoGenerateDeleteButton = True
      customerDetailsView.AllowPaging = True
      customerDetailsView.PagerSettings.Mode = _
        PagerButtons.NextPrevious
      
      Dim keyArray() As String = {"CustomerID"}
      customerDetailsView.DataKeyNames = keyArray

      ' Programmatically register the event-handling method
      ' for the ItemDeleted event of a DetailsView control.
      AddHandler customerDetailsView.ItemDeleted, _
        AddressOf CustomerDetailView_ItemDeleted

      ' Add the DetailsView object to the Controls collection
      ' of the PlaceHolder control.
      DetailsViewPlaceHolder.Controls.Add(customerDetailsView)

    End Sub

    Sub CustomerDetailView_ItemDeleted(ByVal sender As Object, _
      ByVal e As DetailsViewDeletedEventArgs)
  
      ' 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 the numbers of
        ' rows affected by the delete operation.
        If e.AffectedRows = 1 Then
      
          MessageLabel.Text = e.AffectedRows.ToString() _
            & " record deleted successfully."
      
        Else
              
          MessageLabel.Text = e.AffectedRows.ToString() _
            & " records deleted successfully."
      
        End If
    
      Else
    
        ' Insert the code to handle the exception.
        MessageLabel.Text = e.Exception.Message
      
        ' Use the ExceptionHandled property to indicate that the 
        ' exception is already handled.
        e.ExceptionHandled = True
    
      End If
    
    End Sub
  
  </script>
    
  <head runat="server">
    <title>DetailsViewDeletedEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeletedEventHandler Example</h3>
        
        <!-- Use a PlaceHolder control as the container for the -->
        <!-- dynamically generated DetailsView control.         -->       
        <asp:PlaceHolder id="DetailsViewPlaceHolder"
          runat="server"/>
          
        <br/><br/>
        
        <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="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          connectionstring=
            "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

Nell'esempio di codice riportato di seguito viene illustrato come aggiungere in modo dichiarativo un delegato DetailsViewDeletedEventHandler all'evento ItemDeleted di un controllo DetailsView.The following code example demonstrates how to declaratively add a DetailsViewDeletedEventHandler delegate to the ItemDeleted event of a DetailsView control.


<%@ page language="C#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
  
  <script runat="server">

    void CustomerDetailView_ItemDeleted(Object sender, 
      DetailsViewDeletedEventArgs 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 the numbers of
        // rows affected by the delete operation.
        if (e.AffectedRows == 1)
        {
          MessageLabel.Text = e.AffectedRows.ToString() 
            + " record deleted successfully.";
        }
        else
        {
          MessageLabel.Text = e.AffectedRows.ToString() 
            + " records deleted successfully.";
        }
      }
      else
      {
        // Insert the code to handle the exception.
        MessageLabel.Text = e.Exception.Message;

        // Use the ExceptionHandled property to indicate that the 
        // exception is already handled.
        e.ExceptionHandled = true;
      }
    }
  
  </script>
    
  <head runat="server">
    <title>DetailsViewDeletedEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeletedEventHandler Example</h3>
        
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogeneratedeletebutton="true"
          allowpaging="true"
          datakeynames="CustomerID" 
          runat="server">
        
          <pagersettings mode="NextPrevious"/>
        
        </asp:detailsview>
          
        <br/><br/>
        
        <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="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          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">
<html xmlns="http://www.w3.org/1999/xhtml" >
  
  <script runat="server">

    Sub CustomerDetailView_ItemDeleted(ByVal sender As Object, _
      ByVal e As DetailsViewDeletedEventArgs)
  
      ' 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 the numbers of
        ' rows affected by the delete operation.
        If e.AffectedRows = 1 Then
      
          MessageLabel.Text = e.AffectedRows.ToString() _
            & " record deleted successfully."
      
        Else
              
          MessageLabel.Text = e.AffectedRows.ToString() _
            & " records deleted successfully."
      
        End If
    
      Else
    
        ' Insert the code to handle the exception.
        MessageLabel.Text = e.Exception.Message
      
        ' Use the ExceptionHandled property to indicate that the 
        ' exception is already handled.
        e.ExceptionHandled = True
    
      End If
    
    End Sub
  
  </script>
    
  <head runat="server">
    <title>DetailsViewDeletedEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>DetailsViewDeletedEventHandler Example</h3>
        
        <asp:detailsview id="CustomerDetailsView"
          datasourceid="DetailsViewSource"
          autogeneraterows="true"
          autogeneratedeletebutton="true"
          allowpaging="true"
          datakeynames="CustomerID" 
          runat="server">
        
          <pagersettings mode="NextPrevious"/>
        
        </asp:detailsview>
          
        <br/><br/>
        
        <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="DetailsViewSource"
          selectcommand="Select [CustomerID], [CompanyName], [Address], 
            [City], [PostalCode], [Country] From [Customers]"
          deletecommand="Delete [Customers] 
            Where [CustomerID]=@CustomerID"
          connectionstring=
            "<%$ ConnectionStrings:NorthWindConnectionString%>" 
          runat="server"/>
            
      </form>
  </body>
</html>

Remarks

Il controllo DetailsView genera l'evento ItemDeleted quando si fa clic su un pulsante Elimina (un pulsante con la relativa proprietà CommandName impostata su "Delete") all'interno del controllo, ma dopo che il controllo DetailsView eliminato il record.The DetailsView 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 DetailsView control deletes the record. In questo modo è possibile fornire un gestore 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 handler that performs a custom routine, such as checking the results of a delete operation, whenever this event occurs.

Quando si crea un delegato DetailsViewDeletedEventHandler, si identifica il metodo che gestirà l'evento.When you create a DetailsViewDeletedEventHandler delegate, you identify the method that will handle the event. Per associare l'evento al gestore eventi in uso, aggiungere all'evento un'istanza del delegato.To associate the event with your event handler, add an instance of the delegate to the event. Il gestore eventi viene chiamato ogni volta che si verifica l'evento, a meno che non venga rimosso il delegato.The event handler is called whenever the event occurs, unless you remove the delegate. Per ulteriori informazioni sui delegati del gestore eventi, vedere gestione e generazione di eventi.For more information about event-handler delegates, see Handling and Raising Events.

Extension Methods

GetMethodInfo(Delegate)

Ottiene un oggetto che rappresenta il metodo rappresentato dal delegato specificato.Gets an object that represents the method represented by the specified delegate.

Applies to

See also