.net core 3. Unload assemblies

Question

I don't understand why in this situation context is not unload

class Program
{
    static void Main(string[] args)
    {
        CustomAssemblyLoadContext context = new CustomAssemblyLoadContext();
        Assembly assembly = context.LoadFromAssemblyPath(@"C:\Users\Greedy\source\repos\ConsoleApp1\MyApp\bin\Debug\netcoreapp3.1\MyApp.dll");
        context.Unload();
        
        GC.Collect();
        GC.WaitForPendingFinalizers();

        foreach (Assembly asm in AppDomain.CurrentDomain.GetAssemblies())
            Console.WriteLine(asm.GetName().Name);

        Console.Read();
    }

But now context context is successfully unloaded.

    class Program
{
    static void Main(string[] args)
    {
        CustomAssemblyLoadContext context = new CustomAssemblyLoadContext();
        Load(context);
        context.Unload();
        
        GC.Collect();
        GC.WaitForPendingFinalizers();

        foreach (Assembly asm in AppDomain.CurrentDomain.GetAssemblies())
            Console.WriteLine(asm.GetName().Name);

        Console.Read();
    }

    static void Load(CustomAssemblyLoadContext context)
    {
        Assembly assembly = context.LoadFromAssemblyPath(@"C:\Users\Greedy\source\repos\ConsoleApp1\MyApp\bin\Debug\netcoreapp3.1\MyApp.dll");
    }

Why? and how i can fix unload in first example?

What is `CustomAssemblyLoadContext`? – Tanveer Badar Sep 06 '20 at 18:14 — Tanveer Badar, Sep 06 '20 at 18:14
https://stackoverflow.com/a/17131389/17034 – Hans Passant Sep 06 '20 at 19:00 — Hans Passant, Sep 06 '20 at 19:00

score 1 · Answer 1 · answered Sep 06 '20 at 18:17

1

It looks to me like your assembly variable is holding a reference to your loaded DLL.

It works in the second example because you've declared assembly as a local variable of a method, so the variable goes out of scope when control flow leaves the method.

There are other caveats. See here.

answered Sep 06 '20 at 18:17

Robert Harvey

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Yes. I think too. And problem was in "Debug". -> Details [here](http://stackoverflow.com/a/17131389/17034) – Pavel Sep 06 '20 at 20:20

.net core 3. Unload assemblies

1 Answers1