List with timeout/expire ability

Question

I need a function like this:

AddToList(txtName, timeExpire);

It looks like self-descriptive, the item will automatically expire and removed

Answer 1

Just a quick example for the answer Will gave

Add reference to System.Runtime.Caching

 MemoryCache cache = new MemoryCache("CacheName");

 cache.Add(key, value, new CacheItemPolicy() 
                           { AbsoluteExpiration = DateTime.UtcNow.AddSeconds(20) });

You can then check if something is still in the cache by going

 if (cache.Contains(key))

And if you want your cache to have a low time limit then you will need to change the refresh time of the cache with a nice little hack.

MemoryCache AbsoluteExpiration acting strange