public class Messager
{
 private static Messager _MessageInstance;
 private Dictionary<string,Action> _MessageCollection=new Dictionary<string,Action> ();
 private Dictionary<string, ActionClass> _MessageTCollection = new Dictionary<string, ActionClass>();

 public static Messager Default
 {
  get
  {
   if (_MessageInstance == null)
   {
    _MessageInstance = new Messager();
   }
   return _MessageInstance;
  }
 }

 public void Register(string key,Action action)
 {
  _MessageCollection.Add(key,action);
 }

 public void Register<T>(string key, Action<T> action)
 {
  ActionClass<T> actionClass = new ActionClass<T>();
  actionClass.action = action;
  _MessageTCollection.Add(key, actionClass);
 }

 public void Send(string key)
 {
  if (_MessageCollection.Keys.Contains(key))
  {
   _MessageCollection[key].Invoke();
  }
 }

 public void Send<T>(string key,T para)
 {
  if (_MessageTCollection.Keys.Contains(key))
  {
   ActionClass<T> actionClass=(ActionClass<T>) _MessageTCollection[key];
   actionClass.action.Invoke(para);
  }
 }
}

Messager.Default.Register<string>("ChangeControlShow", ExecuteChangedContrlShow);
private void ExecuteChangedContrlShow(string msg)
{
//some code...
}

Messager.Default.Send<string>("ChangeControlShow","test");