WeakReference

Have you ever wanted to store a time consuming to construct object in a cache, but then it hangs around forever. Try storing a WeakReference to the object instead.

            object cached = new TimeConsumingToConstructObject();

            WeakReference wr = new WeakReference(cached);

            cached = null;

            if(wr.IsAlive) {

                cached = wr.Target;

            } else {

                cached = new TimeConsumingToConstructObject();

            }