Garbage collection of C closure

Today, when analyzing the problems of project memory release and garbage collection , Noticed a problem , If a variable is referenced by a closure , Will not be recycled （ This is nonsense in theory ）, That's it , This problem becomes very difficult to check . It means , Some buttons are bound to events with closures , This part of memory is hard to recycle . Here's an example ：

public class B
{
    public int Name;
}

class TestClass
{
    private Action action;
    private static WeakReference<B> weak;
    
    public void GenerateClosure()
    {
        B b = new B();
        weak = new WeakReference<B>(b);
        action = () =>
        {
            Console.WriteLine(b.Name);
        };
    }

    public void ReleaseClosure()
    {
        action = null;
    }

    public void OverWatchGC()
    {
        if (weak.TryGetTarget(out B b))
        {
            Console.WriteLine("B Not recycled ");
        }
        else
        {
            Console.WriteLine("B It's recycled ");
        }
    }
}


class Program
{
    public static void Main(string[] args)
    {
        TestClass c = new TestClass();
        c.GenerateClosure();
        GC.Collect();
        c.OverWatchGC();
        c.ReleaseClosure();
        GC.Collect();
        c.OverWatchGC();
    }
}

give the result as follows ：

B Not recycled
B It's recycled
 

If the function where the closure is located is a static function , Recycling will be more troublesome , I'm testing , Even if you put action Set as null, Garbage collection has not been successful B References to .

So be careful, be careful, be careful , Sometimes a dot accumulates , It is a very difficult problem to check

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