AppDomainUnloadedException Classe

Definição

public ref class AppDomainUnloadedException : SystemException

[System.Runtime.InteropServices.ComVisible(true)]
[System.Serializable]
public class AppDomainUnloadedException : SystemException

type AppDomainUnloadedException = class
    inherit SystemException

Public Class AppDomainUnloadedException
Inherits SystemException

Herança

Object

Exception

SystemException

AppDomainUnloadedException

Atributos

ComVisibleAttribute SerializableAttribute

Exemplos

Esta seção contém dois exemplos de código.This section contains two code examples. O primeiro exemplo demonstra os efeitos de um AppDomainUnloadedException em vários threads e o segundo mostra elementar descarregar domínio do aplicativo.The first example demonstrates the effects of an AppDomainUnloadedException on various threads, and the second shows elementary application domain unloading.

Exemplo 1Example 1

O exemplo de código a seguir define uma TestClass classe que pode ser empacotado entre limites de domínio de aplicativo e uma Example classe que contém uma static (Shared no Visual Basic) ThreadProc método.The following code example defines a TestClass class that can be marshaled across application domain boundaries and an Example class containing a static (Shared in Visual Basic) ThreadProc method. O ThreadProc método cria um domínio de aplicativo, cria um TestClass objeto no domínio e chama um método de TestClass que descarrega o domínio em execução, fazendo com que um AppDomainUnloadedException.The ThreadProc method creates an application domain, creates a TestClass object in the domain, and calls a method of TestClass that unloads the executing domain, causing an AppDomainUnloadedException.

O TestClass método é executado sem tratamento de exceções um ThreadPool thread e de um thread comum, demonstrando que a exceção sem tratamento encerra a tarefa ou thread, mas não o aplicativo.The TestClass method is executed without exception handling from a ThreadPool thread and from an ordinary thread, demonstrating that the unhandled exception terminates the task or thread but not the application. Em seguida, ele é executado com e sem tratamento do thread do aplicativo principal, demonstrando que ele encerra o aplicativo se não forem manipulados de exceção.It is then executed with and without exception handling from the main application thread, demonstrating that it terminates the application if not handled.

using System;
using System.Threading;
using System.Runtime.InteropServices;

public class Example
{
    public static void Main()
    {
        // 1. Queue ThreadProc as a task for a ThreadPool thread.
        ThreadPool.QueueUserWorkItem(ThreadProc, " from a ThreadPool thread");
        Thread.Sleep(1000);

        // 2. Execute ThreadProc on an ordinary thread.
        Thread t = new Thread(ThreadProc);
        t.Start(" from an ordinary thread");
        t.Join();

        // 3. Execute ThreadProc on the main thread, with 
        //    exception handling.
        try
        {
            ThreadProc(" from the main application thread (handled)");
        }
        catch (AppDomainUnloadedException adue)
        {
            Console.WriteLine("Main thread caught AppDomainUnloadedException: {0}", adue.Message);
        }

        // 4. Execute ThreadProc on the main thread without
        //    exception handling.
        ThreadProc(" from the main application thread (unhandled)");

        Console.WriteLine("Main: This message is never displayed.");
    }

    private static void ThreadProc(object state)
    {
        // Create an application domain, and create an instance
        // of TestClass in the application domain. The first
        // parameter of CreateInstanceAndUnwrap is the name of
        // this executable. If you compile the example code using
        // any name other than "Sample.exe", you must change the
        // parameter appropriately.
        AppDomain ad = AppDomain.CreateDomain("TestDomain");
        TestClass tc = (TestClass)ad.CreateInstanceAndUnwrap("Sample", "TestClass");

        // In the new application domain, execute a method that
        // unloads the AppDomain. The unhandled exception this
        // causes ends the current thread.
        tc.UnloadCurrentDomain(state);

        Console.WriteLine("ThreadProc: This message is never displayed.");
    }
}

// TestClass derives from MarshalByRefObject, so it can be marshaled
// across application domain boundaries. 
//
public class TestClass : MarshalByRefObject
{
    public void UnloadCurrentDomain(object state)
    {
        Console.WriteLine("\nUnloading the current AppDomain{0}.", state);
 
        // Unload the current application domain. This causes
        // an AppDomainUnloadedException to be thrown.
        //
        AppDomain.Unload(AppDomain.CurrentDomain);
    }
}

/* This code example produces output similar to the following:
Unloading the current AppDomain from a ThreadPool thread.

Unloading the current AppDomain from an ordinary thread.

Unloading the current AppDomain from the main application thread (handled).
Main thread caught AppDomainUnloadedException: The application domain in which the thread was running has been unloaded.

Unloading the current AppDomain from the main application thread (unhandled).

Unhandled Exception: System.AppDomainUnloadedException: The application domain in which the thread was running has been unloaded.
   at TestClass.UnloadCurrentDomain(Object state)
   at Example.ThreadProc(Object state)
   at Example.Main()
 */

Imports System.Threading
Imports System.Runtime.InteropServices

Public Class Example
    
    Public Shared Sub Main() 

        ' 1. Queue ThreadProc as a task for a ThreadPool thread.
        ThreadPool.QueueUserWorkItem(AddressOf ThreadProc, _
            " from a ThreadPool thread")
        Thread.Sleep(1000)
        
        ' 2. Execute ThreadProc on an ordinary thread.
        Dim t As New Thread(AddressOf ThreadProc)
        t.Start(" from an ordinary thread")
        t.Join()
        
        ' 3. Execute ThreadProc on the main thread, with 
        '    exception handling.
        Try
            ThreadProc(" from the main application thread (handled)")
        Catch adue As AppDomainUnloadedException
            Console.WriteLine("Main thread caught AppDomainUnloadedException: {0}", _
                adue.Message)
        End Try
        
        ' 4. Execute ThreadProc on the main thread without
        '    exception handling.
        ThreadProc(" from the main application thread (unhandled)")
        
        Console.WriteLine("Main: This message is never displayed.")
    
    End Sub 
    
    Private Shared Sub ThreadProc(ByVal state As Object) 
        ' Create an application domain, and create an instance
        ' of TestClass in the application domain. The first
        ' parameter of CreateInstanceAndUnwrap is the name of
        ' this executable. If you compile the example code using
        ' any name other than "Sample.exe", you must change the
        ' parameter appropriately.
        Dim ad As AppDomain = AppDomain.CreateDomain("TestDomain")
        Dim o As Object = ad.CreateInstanceAndUnwrap("Sample", "TestClass")
        Dim tc As TestClass = CType(o, TestClass)
        
        ' In the new application domain, execute a method that
        ' unloads the AppDomain. The unhandled exception this
        ' causes ends the current thread.
        tc.UnloadCurrentDomain(state)
        
        Console.WriteLine("ThreadProc: This message is never displayed.")
    
    End Sub
End Class 

' TestClass derives from MarshalByRefObject, so it can be marshaled
' across application domain boundaries. 
'
Public Class TestClass
    Inherits MarshalByRefObject
    
    Public Sub UnloadCurrentDomain(ByVal state As Object) 
        Console.WriteLine(vbLf & "Unloading the current AppDomain{0}.", state)
        
        ' Unload the current application domain. This causes
        ' an AppDomainUnloadedException to be thrown.
        '
        AppDomain.Unload(AppDomain.CurrentDomain)
    
    End Sub 
End Class 

' This code example produces output similar to the following:
'
'Unloading the current AppDomain from a ThreadPool thread.
'
'Unloading the current AppDomain from an ordinary thread.
'
'Unloading the current AppDomain from the main application thread (handled).
'Main thread caught AppDomainUnloadedException: The application domain in which the thread was running has been unloaded.
'
'Unloading the current AppDomain from the main application thread (unhandled).
'
'Unhandled Exception: System.AppDomainUnloadedException: The application domain in which the thread was running has been unloaded.
'   at TestClass.UnloadCurrentDomain(Object state)
'   at Example.ThreadProc(Object state)
'   at Example.Main()
' 

Exemplo 2Example 2

O exemplo de código a seguir cria um domínio de aplicativo é descarregado e demonstra que um AppDomainUnloadedException será lançada em uma tentativa subsequente de acessar o domínio descarregado.The following code example creates and unloads an application domain, and demonstrates that an AppDomainUnloadedException is thrown on a subsequent attempt to access the unloaded domain.

using namespace System;
using namespace System::Reflection;
using namespace System::Security::Policy;

//for evidence Object*
int main()
{
   
   //Create evidence for the new appdomain.
   Evidence^ adevidence = AppDomain::CurrentDomain->Evidence;
   
   // Create the new application domain.
   AppDomain^ domain = AppDomain::CreateDomain( "MyDomain", adevidence );
   Console::WriteLine( "Host domain: {0}", AppDomain::CurrentDomain->FriendlyName );
   Console::WriteLine( "child domain: {0}", domain->FriendlyName );
   
   // Unload the application domain.
   AppDomain::Unload( domain );
   try
   {
      Console::WriteLine();
      
      // Note that the following statement creates an exception because the domain no longer exists.
      Console::WriteLine( "child domain: {0}", domain->FriendlyName );
   }
   catch ( AppDomainUnloadedException^ /*e*/ ) 
   {
      Console::WriteLine( "The appdomain MyDomain does not exist." );
   }

}

using System;
using System.Reflection;
using System.Security.Policy;
class ADUnload
{
    public static void Main()
    {

        //Create evidence for the new appdomain.
        Evidence adevidence = AppDomain.CurrentDomain.Evidence;

        // Create the new application domain.
        AppDomain domain = AppDomain.CreateDomain("MyDomain", adevidence);

                Console.WriteLine("Host domain: " + AppDomain.CurrentDomain.FriendlyName);
                Console.WriteLine("child domain: " + domain.FriendlyName);
        // Unload the application domain.
        AppDomain.Unload(domain);

        try
        {
        Console.WriteLine();
        // Note that the following statement creates an exception because the domain no longer exists.
                Console.WriteLine("child domain: " + domain.FriendlyName);
        }

        catch (AppDomainUnloadedException e)
        {
        Console.WriteLine("The appdomain MyDomain does not exist.");
        }
        
    }
    
}

Imports System.Reflection
Imports System.Security.Policy

Class ADUnload
   
   Public Shared Sub Main()

      'Create evidence for the new appdomain.
      Dim adevidence As Evidence = AppDomain.CurrentDomain.Evidence

      ' Create the new application domain.
      Dim domain As AppDomain = AppDomain.CreateDomain("MyDomain", adevidence)
      
      Console.WriteLine(("Host domain: " + AppDomain.CurrentDomain.FriendlyName))
      Console.WriteLine(("child domain: " + domain.FriendlyName))
      ' Unload the application domain.
      AppDomain.Unload(domain)
      
      Try
         Console.WriteLine()
         ' Note that the following statement creates an exception because the domain no longer exists.
         Console.WriteLine(("child domain: " + domain.FriendlyName))
      
      Catch e As AppDomainUnloadedException
         Console.WriteLine("The appdomain MyDomain does not exist.")
      End Try
   End Sub
End Class

Comentários

No .NET Framework versão 2.0, um AppDomainUnloadedException que é o usuário não tratado no código tem o seguinte efeito:In the .NET Framework version 2.0, an AppDomainUnloadedException that is not handled in user code has the following effect:

• Se um thread foi iniciado em código gerenciado, ela será encerrada.If a thread was started in managed code, it is terminated. A exceção sem tratamento não tem permissão para encerrar o aplicativo.The unhandled exception is not allowed to terminate the application.

• Se uma tarefa está em execução em um ThreadPool thread, ela será encerrada e o thread é retornado ao pool de threads.If a task is executing on a ThreadPool thread, it is terminated and the thread is returned to the thread pool. A exceção sem tratamento não tem permissão para encerrar o aplicativo.The unhandled exception is not allowed to terminate the application.

• Se um thread foi iniciado no código não gerenciado, como o thread principal do aplicativo, ele será encerrado.If a thread started in unmanaged code, such as the main application thread, it is terminated. A exceção sem tratamento tem permissão para prosseguir, e o sistema operacional encerre o aplicativo.The unhandled exception is allowed to proceed, and the operating system terminates the application.

AppDomainUnloadedException usa o HRESULT COR_E_APPDOMAINUNLOADED, que tem o valor 0x80131014.AppDomainUnloadedException uses the HRESULT COR_E_APPDOMAINUNLOADED, which has the value 0x80131014.

Para obter uma lista de valores de propriedade inicial para uma instância do AppDomainUnloadedException, consulte o AppDomainUnloadedException construtores.For a list of initial property values for an instance of AppDomainUnloadedException, see the AppDomainUnloadedException constructors.

Construtores

Propriedades

Métodos

Eventos

Aplica-se a

Veja também

• AppDomain
• Exception
• Tratando e gerando exceções no .NETHandling and throwing exceptions in .NET