这对静态类很好用吗？

Question

I have a read only list that is shared across all instances of the application and won't change very often. Is it good practice to make a property on a static class to access this list? the list is filled from the database in the static constructor. Setting the app pool to recycle every night would guarantee the list would be up to date every day correct? Are there any reasons this is a bad idea? Thanks!

Answer 1

This looks like a good solution. You may want to use a sealed class instead, to avoid sub-classes messing with it.

The issue with global state is when it is being changed by the application. In this case, that's not a problem.

Answer 2

Nothing wrong with a static class. You could also use the cache, which would work in a similar way. The cache gives you the added bonus of being able to invalidate the cache on a timed basis of your choosing.

Answer 3

You should understand how static properties are stored.

Roughly, all static state is placed in the instance of RuntimeType (which, in turn, is created when static ctor is called). CLR via C# describes this mechanism in details.

In the light of that, this collection will be shared across all instances, but you should keep in mind all potential memory leaks (just imagine the situation when you're subscribing on the collection events and all pages became reachable even when they're closed etc.)

The second disadvantage of this approach is that this collection is not up-to-date. The third disadvantage is that you need to take care about thread safety of this collection, which, in turn, will harm your performance.