DetailsViewDeletedEventHandler Delegar

Definição

Representa o método que gere o ItemDeleted evento de um DetailsView controlo.

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)

Parâmetros

sender
Object

A origem do evento.

e
DetailsViewDeletedEventArgs

A DetailsViewDeletedEventArgs que contém os dados do evento.

Exemplos

O exemplo de código seguinte demonstra como adicionar programaticamente um DetailsViewDeletedEventHandler delegado ao ItemDeleted evento de um DetailsView controlo.


<%@ 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>

O exemplo de código seguinte demonstra como adicionar declarativamente um DetailsViewDeletedEventHandler delegado ao ItemDeleted evento de um DetailsView controlo.


<%@ 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>

Observações

O DetailsView controlo levanta o ItemDeleted evento quando um botão Delete (um botão com CommandName a propriedade definida para "Eliminar") dentro do controlo é clicado, mas depois de o DetailsView controlo apagar o registo. Isto permite-lhe fornecer um gestor de eventos que executa uma rotina personalizada, como verificar os resultados de uma operação de eliminação, sempre que este evento ocorre.

Quando cria um DetailsViewDeletedEventHandler delegado, identifica o método que irá gerir o evento. Para associar o evento ao seu gestor de eventos, adicione uma instância do delegado ao evento. O gestor de eventos é chamado sempre que o evento ocorre, a menos que remova o delegado. Para mais informações sobre os delegados handlers de eventos, consulte Gestão e Angariação de Eventos.

Métodos da Extensão

Name Description
GetMethodInfo(Delegate)

Obtém um objeto que representa o método representado pelo delegado especificado.

Aplica-se a

Ver também