Binding.Parse Evento

Definición

Se produce cuando cambia el valor de un control con enlace a datos.Occurs when the value of a data-bound control changes.

public:
 event System::Windows::Forms::ConvertEventHandler ^ Parse;
public event System.Windows.Forms.ConvertEventHandler Parse;
member this.Parse : System.Windows.Forms.ConvertEventHandler 
Public Custom Event Parse As ConvertEventHandler 

Tipo de evento

ConvertEventHandler

Ejemplos

En el ejemplo de código siguiente Binding se crea un, se agrega un ConvertEventHandler delegado a los Parse Format eventos y y Binding se agrega a la BindingsCollection de un TextBox control a través de la DataBindings propiedad.The following code example creates a Binding, adds a ConvertEventHandler delegate to both the Parse and Format events, and adds the Binding to the BindingsCollection of a TextBox control through the DataBindings property. El DecimalToCurrencyString delegado de eventos, que se agrega al Format evento, da formato al valor enlazado (un Decimal tipo) como moneda mediante el ToString método.The DecimalToCurrencyString event delegate, added to the Format event, formats the bound value (a Decimal type) as currency using the ToString method. El CurrencyStringToDecimal delegado de eventos, que se agrega al Parse evento, convierte el valor mostrado por el control de nuevo Decimal al tipo.The CurrencyStringToDecimal event delegate, added to the Parse event, converts the value displayed by the control back to the Decimal type.

private:
   void DecimalToCurrencyString( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      // The method converts only to string type. Test this using the DesiredType.
      if ( cevent->DesiredType != String::typeid )
      {
         return;
      }
      
      // Use the ToString method to format the value as currency ("c").
      cevent->Value = ( (Decimal)(cevent->Value) ).ToString( "c" );
   }

   void CurrencyStringToDecimal( Object^ /*sender*/, ConvertEventArgs^ cevent )
   {
      // The method converts back to decimal type only.
      if ( cevent->DesiredType != Decimal::typeid )
      {
         return;
      }
      
      // Converts the string back to decimal using the static Parse method.
      cevent->Value = Decimal::Parse( cevent->Value->ToString(),
         NumberStyles::Currency, nullptr );
   }

   void BindControl()
   {
      // Creates the binding first. The OrderAmount is typed as Decimal.
      Binding^ b = gcnew Binding(
         "Text", ds, "customers.custToOrders.OrderAmount" );
      // Add the delegates to the event.
      b->Format += gcnew ConvertEventHandler( this, &Form1::DecimalToCurrencyString );
      b->Parse += gcnew ConvertEventHandler( this, &Form1::CurrencyStringToDecimal );
      text1->DataBindings->Add( b );
   }
private void DecimalToCurrencyString(object sender, ConvertEventArgs cevent)
{
   // The method converts only to string type. Test this using the DesiredType.
   if(cevent.DesiredType != typeof(string)) return;

   // Use the ToString method to format the value as currency ("c").
   cevent.Value = ((decimal) cevent.Value).ToString("c");
}

private void CurrencyStringToDecimal(object sender, ConvertEventArgs cevent)
{
   // The method converts back to decimal type only.
   if(cevent.DesiredType != typeof(decimal)) return;

   // Converts the string back to decimal using the static Parse method.
   cevent.Value = Decimal.Parse(cevent.Value.ToString(),
   NumberStyles.Currency, null);
}

private void BindControl()
{
   // Creates the binding first. The OrderAmount is typed as Decimal.
   Binding b = new Binding
      ("Text", ds, "customers.custToOrders.OrderAmount");
   // Add the delegates to the event.
   b.Format += new ConvertEventHandler(DecimalToCurrencyString);
   b.Parse += new ConvertEventHandler(CurrencyStringToDecimal);
   text1.DataBindings.Add(b);
}

Private Sub DecimalToCurrencyString(sender As Object, cevent As ConvertEventArgs)
    ' The method converts only to string type. Test this using the DesiredType.
    If cevent.DesiredType IsNot GetType(String) Then
        Exit Sub
    End If
    
    ' Use the ToString method to format the value as currency ("c").
    cevent.Value = CType(cevent.Value, decimal).ToString("c")
End Sub

Private Sub CurrencyStringToDecimal(sender As Object, cevent As ConvertEventArgs)
    ' The method converts back to decimal type only.
    If cevent.DesiredType IsNot GetType(Decimal) Then
        Exit Sub
    End If

    ' Convert the string back to decimal using the shared Parse method.
   cevent.Value = Decimal.Parse(cevent.Value.ToString, _
  NumberStyles.Currency, nothing)

End Sub

Private Sub BindControl
    ' Create the binding first. The OrderAmount is typed as Decimal.
    Dim b As Binding = New Binding _
        ("Text", ds, "Customers.custToOrders.OrderAmount")
    ' Add the delegates to the event.
    AddHandler b.Format, AddressOf DecimalToCurrencyString
    AddHandler b.Parse, AddressOf CurrencyStringToDecimal
    text1.DataBindings.Add(b)
End Sub

Comentarios

Los Format Parse eventos y permiten crear formatos personalizados para mostrar los datos.The Format and Parse events allow you to create custom formats for displaying data. Por ejemplo, si los datos de una tabla son de tipo Decimal , puede mostrar los datos en el formato de moneda local estableciendo la Value propiedad de ConvertEventArgs en el valor con formato en el Format evento.For example, if the data in a table is of type Decimal, you can display the data in the local currency format by setting the Value property of the ConvertEventArgs to the formatted value in the Format event. En consecuencia, debe desformatear el valor mostrado en el Parse evento.You must consequently unformat the displayed value in the Parse event.

El Parse evento se produce en las siguientes condiciones:The Parse event occurs under the following conditions:

Para obtener más información sobre el manejo de eventos, consulte controlar y provocar eventos.For more information about handling events, see Handling and Raising Events.

Se aplica a

Consulte también