AppDomain.Unload(AppDomain) AppDomain.Unload(AppDomain) AppDomain.Unload(AppDomain) AppDomain.Unload(AppDomain) Method

Definition

Unloads the specified application domain.

public:
 static void Unload(AppDomain ^ domain);
public static void Unload (AppDomain domain);
static member Unload : AppDomain -> unit
Public Shared Sub Unload (domain As AppDomain)

Parameters

domain
AppDomain AppDomain AppDomain AppDomain

An application domain to unload.

Exceptions

An error occurred during the unload process.

Examples

The following code example shows how to unload an application 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
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 'Main 
End Class 'ADUnload

Remarks

In the .NET Framework version 2.0 there is a thread dedicated to unloading application domains. This improves reliability, especially when the .NET Framework is hosted. When a thread calls Unload, the target domain is marked for unloading. The dedicated thread attempts to unload the domain, and all threads in the domain are aborted. If a thread does not abort, for example because it is executing unmanaged code, or because it is executing a finally block, then after a period of time a CannotUnloadAppDomainException is thrown in the thread that originally called Unload. If the thread that could not be aborted eventually ends, the target domain is not unloaded. Thus, in the .NET Framework version 2.0 domain is not guaranteed to unload, because it might not be possible to terminate executing threads.

Note

In some cases, calling Unload causes an immediate CannotUnloadAppDomainException, for example if it is called in a finalizer.

The threads in domain are terminated using the Abort method, which throws a ThreadAbortException in the thread. Although the thread should terminate promptly, it can continue executing for an unpredictable amount of time in a finally clause.

Version Compatibility

In the .NET Framework version 1.0 and 1.1 if the thread that calls Unload is running in domain, another thread is started to perform the unload operation. If domain cannot be unloaded, a CannotUnloadAppDomainException is thrown in that thread, not in the original thread that called Unload. However, if the thread that calls Unload is running outside domain, that thread receives the exception.

Security

SecurityPermission
to add an event handler for this event. Associated enumeration: ControlAppDomain. Security action: Demand.

Applies to