Thanks for the answer, but forcing GC (Garbage collector) isn't good practice and how should we as developers know that map with specific layer needs manual call of GC?
When I think about it, it looks like there are probably objects that are moved to GC's Large Object Heap and thus they get collected after a long time (if ever) because they live in second generation of GC.
When you know, that using layers such as ArcGISTiledMapServiceLayer creates those objects (many smaller ones or few big ones?), shouldn't the SDK, instead of those who use it, take special care of those layers when map is unloaded?
I think it could be considered as bug, because when unloading and loading few maps with several layers, you quickly run out of memory and this is something no one would expect, because everyone hopes GC takes care of controls that are no longer loaded.
Thank you.