Using lock on the key of a Dictionary

Question

I have a Dictionary.

EDIT: It was pointed out to me, that my example was bad. My whole intention was not to update the references

Answer 1

Just came across this and thought id share some code I wrote a few years ago where I needed to a dictionary on a key basis

 using (var lockObject = new Lock(hashedCacheID))
 {
    var lockedKey = lockObject.GetLock();
    //now do something with the dictionary
 }

the lock class

class Lock : IDisposable
    {
        private static readonly Dictionary Lockedkeys = new Dictionary();

        private static readonly object CritialLock = new object();

        private readonly string _key;
        private bool _isLocked;

        public Lock(string key)
        {
            _key = key;

            lock (CritialLock)
            {
                //if the dictionary doesnt contain the key add it
                if (!Lockedkeys.ContainsKey(key))
                {
                    Lockedkeys.Add(key, String.Copy(key)); //enusre that the two objects have different references
                }
            }
        }

        public string GetLock()
        {
            var key = Lockedkeys[_key];

            if (!_isLocked)
            {
                Monitor.Enter(key);
            }
            _isLocked = true;

            return key;
        }

        public void Dispose()
        {
            var key = Lockedkeys[_key];

            if (_isLocked)
            {
                Monitor.Exit(key);
            }
            _isLocked = false;
        }
    }