AsyncCompletedEventArgs.RaiseExceptionIfNecessary AsyncCompletedEventArgs.RaiseExceptionIfNecessary AsyncCompletedEventArgs.RaiseExceptionIfNecessary AsyncCompletedEventArgs.RaiseExceptionIfNecessary Method

Definición

Genera una excepción proporcionada por el usuario si se ha producido un error en una operación asincrónica.Raises a user-supplied exception if an asynchronous operation failed.

protected:
 void RaiseExceptionIfNecessary();
protected void RaiseExceptionIfNecessary ();
member this.RaiseExceptionIfNecessary : unit -> unit
Protected Sub RaiseExceptionIfNecessary ()

Excepciones

La operación asincrónica ha establecido la propiedad Error.The Error property has been set by the asynchronous operation. La propiedad InnerException contiene una referencia a Error.The InnerException property holds a reference to Error.

Ejemplos

En el ejemplo de código siguiente RaiseExceptionIfNecessary se muestra el uso de en las propiedades de la clase derivada.The following code example demonstrates using RaiseExceptionIfNecessary in derived class properties.

public class CalculatePrimeCompletedEventArgs :
    AsyncCompletedEventArgs
{
    private int numberToTestValue = 0;
    private int firstDivisorValue = 1;
    private bool isPrimeValue;

    public CalculatePrimeCompletedEventArgs(
        int numberToTest,
        int firstDivisor,
        bool isPrime,
        Exception e,
        bool canceled,
        object state) : base(e, canceled, state)
    {
        this.numberToTestValue = numberToTest;
        this.firstDivisorValue = firstDivisor;
        this.isPrimeValue = isPrime;
    }

    public int NumberToTest
    {
        get
        {
            // Raise an exception if the operation failed or 
            // was canceled.
            RaiseExceptionIfNecessary();

            // If the operation was successful, return the 
            // property value.
            return numberToTestValue;
        }
    }

    public int FirstDivisor
    {
        get
        {
            // Raise an exception if the operation failed or 
            // was canceled.
            RaiseExceptionIfNecessary();

            // If the operation was successful, return the 
            // property value.
            return firstDivisorValue;
        }
    }

    public bool IsPrime
    {
        get
        {
            // Raise an exception if the operation failed or 
            // was canceled.
            RaiseExceptionIfNecessary();

            // If the operation was successful, return the 
            // property value.
            return isPrimeValue;
        }
    }
}

Public Class CalculatePrimeCompletedEventArgs
    Inherits AsyncCompletedEventArgs
    Private numberToTestValue As Integer = 0
    Private firstDivisorValue As Integer = 1
    Private isPrimeValue As Boolean


    Public Sub New( _
    ByVal numberToTest As Integer, _
    ByVal firstDivisor As Integer, _
    ByVal isPrime As Boolean, _
    ByVal e As Exception, _
    ByVal canceled As Boolean, _
    ByVal state As Object)

        MyBase.New(e, canceled, state)
        Me.numberToTestValue = numberToTest
        Me.firstDivisorValue = firstDivisor
        Me.isPrimeValue = isPrime

    End Sub


    Public ReadOnly Property NumberToTest() As Integer
        Get
            ' Raise an exception if the operation failed 
            ' or was canceled.
            RaiseExceptionIfNecessary()

            ' If the operation was successful, return 
            ' the property value.
            Return numberToTestValue
        End Get
    End Property


    Public ReadOnly Property FirstDivisor() As Integer
        Get
            ' Raise an exception if the operation failed 
            ' or was canceled.
            RaiseExceptionIfNecessary()

            ' If the operation was successful, return 
            ' the property value.
            Return firstDivisorValue
        End Get
    End Property


    Public ReadOnly Property IsPrime() As Boolean
        Get
            ' Raise an exception if the operation failed 
            ' or was canceled.
            RaiseExceptionIfNecessary()

            ' If the operation was successful, return 
            ' the property value.
            Return isPrimeValue
        End Get
    End Property
End Class

Notas a los desarrolladores de herederos

Si ha derivado su propia clase de la AsyncCompletedEventArgs clase, las propiedades de solo lectura deben llamar al RaiseExceptionIfNecessary() método antes de devolver el valor de la propiedad.If you have derived your own class from the AsyncCompletedEventArgs class, your read-only properties should call the RaiseExceptionIfNecessary() method before returning the property value. Si el código de trabajo asincrónico del componente asigna una excepción a la Error propiedad o establece la Cancelled propiedad en true, la propiedad producirá una excepción si un cliente intenta leer su valor.If the component's asynchronous worker code assigns an exception to the Error property or sets the Cancelled property to true, the property will raise an exception if a client tries to read its value. Esto evita que los clientes tengan acceso a las propiedades que no son válidas debido a un error en la operación asincrónica.This prevents clients from accessing properties that are potentially not valid due to a failure in the asynchronous operation.

Se aplica a

Consulte también: