自定义的事件管理器

　　　　　　　　　　　　　　周银辉

大多数框架下都提供了事件管理器的，但不使用框架时为了让事件发送者和事件接收者之间解耦，就可以如下写个简单的

    public enum EventAdministratorEventTypes{ApplicationStartup, //在这里添加你需要的事件}public class EventAdministratorEventArgs : EventArgs{public object Arg{get;protected set;}public EventAdministratorEventArgs(object arg){Arg = arg;}}public class EventAdministrator{private static EventAdministrator instance;public static EventAdministrator Instance{get { return instance ?? (instance = new EventAdministrator()); }}/// <summary>/// 用于存储event和它对于的回调函数列表的字典(event 和 callback是一对多的关系)/// </summary>private readonly Dictionary<EventAdministratorEventTypes, List<EventHandler<EventAdministratorEventArgs>>> eventAndCallbackBuffer = new Dictionary<EventAdministratorEventTypes, List<EventHandler<EventAdministratorEventArgs>>>();private void AddCallbackForEvent(EventAdministratorEventTypes eventName,EventHandler<EventAdministratorEventArgs> callback){if (!eventAndCallbackBuffer.ContainsKey(eventName)){eventAndCallbackBuffer.Add(eventName, new List<EventHandler<EventAdministratorEventArgs>>());}var callbackList = eventAndCallbackBuffer[eventName];//添加时判定不存在为了防止多次注册后引起多次调用回调函数if (!callbackList.Contains(callback)){callbackList.Add(callback);}}/// <summary>/// 注册为事件接受者/// </summary>/// <param name="eventName">事件名称</param>/// <param name="callback">事件发生时的回调函数</param>public void Register(EventAdministratorEventTypes eventName, EventHandler<EventAdministratorEventArgs> callback){AddCallbackForEvent(eventName, callback);}/// <summary>/// 触发一个事件/// </summary>/// <param name="sender">触发者</param>/// <param name="eventName">事件名称</param>/// <param name="args">触发该事件时所带的参数</param>public void Send(object sender, EventAdministratorEventTypes eventName, EventAdministratorEventArgs args){if (!eventAndCallbackBuffer.ContainsKey(eventName)){Logger.Warning("EventAdministrator:事件"+eventName+"被触发，但没有任何对象注册该事件." +" 导致这个情况的原因可能有：代码中没有调用相应的Register函数来注册该事件； 或者 事件的Send函数发生在Register之前");return;}var callbackList = eventAndCallbackBuffer[eventName];foreach (var callback in callbackList){callback.Invoke(sender, args);}}}
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