ConvertEventArgs Clase

Definición

Proporciona datos para los eventos Format y Parse.Provides data for the Format and Parse events.

public ref class ConvertEventArgs : EventArgs
public class ConvertEventArgs : EventArgs
type ConvertEventArgs = class
    inherit EventArgs
Public Class ConvertEventArgs
Inherits EventArgs
Herencia
ConvertEventArgs
Derivado

Ejemplos

En el ejemplo de código siguiente Bindingse crea un ConvertEventHandler , se agrega un Parse delegado Format a los BindingsCollection eventos y, DataBindings y se usa la Binding propiedad para agregar el TextBox al de un control.The following code example creates a Binding, adds a ConvertEventHandler delegate to both the Parse and Format events, and uses the DataBindings property to add the Binding to the BindingsCollection of a TextBox control. El DecimalToCurrencyString delegado de eventos, que se agrega Format al evento, utiliza el ToString método para dar formato al valor enlazado Decimal (un tipo) como moneda.The DecimalToCurrencyString event delegate, which is added to the Format event, uses the ToString method to format the bound value (a Decimal type) as currency. El CurrencyStringToDecimal delegado de eventos, que se agrega Parse al evento, convierte de nuevo el valor mostrado por Decimal el control al tipo.The CurrencyStringToDecimal event delegate, which is 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" );
      
      // Adds the delegates to the events.
      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");
   // Adds the delegates to the events.
   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 Not cevent.DesiredType Is GetType(String) Then
      Return
   End If 
   ' Use the ToString method to format the value as currency ("c").
   cevent.Value = CDec(cevent.Value).ToString("c")
End Sub
 
 
Private Sub CurrencyStringToDecimal(sender As Object, cevent As ConvertEventArgs)
   ' The method converts back to decimal type only. 
   If Not cevent.DesiredType Is GetType(Decimal) Then
      Return
   End If 
   ' Converts 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()
   ' Creates the binding first. The OrderAmount is typed as Decimal.
   Dim b As New Binding("Text", ds, "customers.custToOrders.OrderAmount")
   ' Adds the delegates to the events.
   AddHandler b.Format, AddressOf DecimalToCurrencyString
   AddHandler b.Parse, AddressOf CurrencyStringToDecimal
   text1.DataBindings.Add(b)
End Sub

Comentarios

Se usa para dar formato y desformatear los valores mostrados por un control Windows Forms que está enlazado Binding a datos a través de un objeto. ConvertEventArgsThe ConvertEventArgs is used to format and unformat values displayed by a Windows Forms control that is bound to data through a Binding object. El Format evento tiene lugar cuando una propiedad de control está enlazada a un Parse valor y el evento tiene lugar cuando cambia el valor enlazado.The Format event occurs whenever a control property is bound to a value and the Parse event occurs whenever the bound value changes.

Los Format eventos Parse 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 especificar que los datos se muestren en el formato de moneda local. ConvertEventArgs para ello, establezca Value la propiedad de en el valor con formato en Format el evento.For example, if the data in a table is of type Decimal, you can specify that the data should be displayed 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 Parse el evento.You must consequently unformat the displayed value in the Parse event.

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.

Constructores

ConvertEventArgs(Object, Type)

Inicializa una nueva instancia de la clase ConvertEventArgs.Initializes a new instance of the ConvertEventArgs class.

Propiedades

DesiredType

Obtiene el tipo de datos del valor deseado.Gets the data type of the desired value.

Value

Obtiene o establece el valor de ConvertEventArgs.Gets or sets the value of the ConvertEventArgs.

Métodos

Equals(Object)

Determina si el objeto especificado es igual al objeto actual.Determines whether the specified object is equal to the current object.

(Heredado de Object)
GetHashCode()

Sirve como la función hash predeterminada.Serves as the default hash function.

(Heredado de Object)
GetType()

Obtiene el Type de la instancia actual.Gets the Type of the current instance.

(Heredado de Object)
MemberwiseClone()

Crea una copia superficial del objeto Object actual.Creates a shallow copy of the current Object.

(Heredado de Object)
ToString()

Devuelve una cadena que representa el objeto actual.Returns a string that represents the current object.

(Heredado de Object)

Se aplica a

Consulte también: