My program creates in anytime new methods (Using MethodBuilder with array of byte\IL) that it executes them once and discard the reference to them. I found that they don't actually affected by the GC. Is there a way to let the GC collect them or dispose them?
I found that the problem is that to create new method, need to load it's assembly that can't be unloaded after. I need to run those methods on the main appdomain. (It creates objects or modifying some)
Is there an alternative to MethodBuilder and just execute those byte\IL anyway?
Use DynamicMethod if you only need to emit a method that can be garbage collected later. From the docs:
Defines and represents a dynamic method that can be compiled, executed, and discarded. Discarded methods are available for garbage collection.
If you need to build a type dynamically then you need to define a dynamic assembly for it that can be collected. To do that use AssemblyBuilder.DefineDynamicAssembly with the AssemblyBuilderAccess.RunAndCollect option. There are some restrictions on what you can do in a collectible assembly detailed here.