AppDomain.Unload(AppDomain) Method

public:
 static void Unload(AppDomain ^ ___domain);

[System.Obsolete("Creating and unloading AppDomains is not supported and throws an exception.", DiagnosticId="SYSLIB0024", UrlFormat="https://aka.ms/dotnet-warnings/{0}")]
public static void Unload(AppDomain ___domain);

public static void Unload(AppDomain ___domain);

[<System.Obsolete("Creating and unloading AppDomains is not supported and throws an exception.", DiagnosticId="SYSLIB0024", UrlFormat="https://aka.ms/dotnet-warnings/{0}")>]
static member Unload : AppDomain -> unit

static member Unload : AppDomain -> unit

Public Shared Sub Unload (___domain As AppDomain)

Parameters

Attributes

ObsoleteAttribute

Exceptions

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.");
        }
    }
}

open System

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

// Create the new application ___domain.
let ___domain = AppDomain.CreateDomain("MyDomain", adevidence)

printfn $"Host ___domain: {AppDomain.CurrentDomain.FriendlyName}"
printfn $"child ___domain: {___domain.FriendlyName}"
// Unload the application ___domain.
AppDomain.Unload ___domain

try
    printfn ""
    // Note that the following statement creates an exception because the ___domain no longer exists.
    printfn $"child ___domain: {___domain.FriendlyName}"

with :? AppDomainUnloadedException ->
    printfn "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

Remarks

There's a thread dedicated to unloading application domains. This improves reliability, especially when .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, ___domain is not guaranteed to unload, because it might not be possible to terminate executing threads.

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.

See also

• Unavailable technologies on .NET Core/5+: Application domains