Excuse me:
Unity3D Unity2018.4.11 (c1) on the script in Visual Studio 2019, add some code, after save, Unity compiled complains (reasons)

After after adding the code to ensure preservation, compiled through Unity, vs open the script file to open (update state before the code for A state that is updated to B state), restart code after the state is in A state, not in state, B is added code didn't, you need to add the save is not, (recently often encounter this problem)

Could you tell me what the situation, have a solution?