Question

Possible Duplicate:
Unloading the Assembly loaded with Assembly.LoadFrom()

I use custom AppDomain to load/unload assembly. But when assembly is unloaded I am able to see it under the AppDomain.CurrentDomain.

How it could be? Is this normal behavior or I am missing something?

Thank you for any clue!

 string assemblyPath = @"C:\MyFile.dll";
 var assemblyName = AssemblyName.GetAssemblyName(assemblyPath);

            var ads = new AppDomainSetup
                          {
                              ApplicationBase = AppDomain.CurrentDomain.SetupInformation.ApplicationBase, 
                              DisallowCodeDownload = true 
                          };

            AppDomain newDomainName = AppDomain.CreateDomain("newDomainName", null, ads);
              try
              {
                  Assembly testLibrary = newDomainName.Load(assemblyName);

                  var c1 = AppDomain.CurrentDomain.GetAssemblies();

                  var c2 = newDomainName.GetAssemblies();
              }
              finally
              {
                  AppDomain.Unload(newDomainName);

                  var c3 = AppDomain.CurrentDomain.GetAssemblies();

                  // The assembly is still visible here!!!
              }

Answer 1

You are calling the Load() method of an AppDomain, which according to the documentation: “should be used only to load an assembly into the current application domain. This method is provided as a convenience for interoperability callers who cannot call the static Assembly.Load method. To load assemblies into other application domains, use a method such as CreateInstanceAndUnwrap.”

In other words, you’re loading the assembly into the primary AppDomain because you’re calling Load() from the primary AppDomain (even though you’re using calling it on an instance of your secondary AppDomain), and this is why it is appearing even after you unload your secondary AppDomain.

As indicated in the extract from the documentation above, you probably want to use AppDomain.CreateInstanceAndUnwrap.