/// 
    /// 使用之前在App.Config中初始化Initialize()    /// 
    public static class DispatcherHelper    {        public static Dispatcher UiDispatcher { get; private set; }        /// 
        /// 检查操作是否是在UI线程上。假如操作在UI线程上则直接执行，否则调用UI Dispatcher线程执行。        /// 
        ///         public static void CheckBeginInvokeOnUi(Action action)        {            if (action == null) return;            CheckDispatcher();            if (UiDispatcher.CheckAccess())            {                action();            }            else            {                UiDispatcher.BeginInvoke(action);            }        }        private static void CheckDispatcher()        {            if (UiDispatcher == null)            {                var error = new StringBuilder("The DispatcherHelper is not initialized.");                error.AppendLine();                throw new InvalidOperationException(error.ToString());            }        }        /// 
        /// 在UI线程上执行异步操作        /// 
        ///         /// 
             public static DispatcherOperation RunAsync(Action action)        {            CheckDispatcher();            return UiDispatcher.BeginInvoke(action);        }        /// 
        /// 在APP.Config的Application_Startup中初始化Initialize        /// 
        public static void Initialize()        {            if (UiDispatcher != null && UiDispatcher.Thread.IsAlive)            {                return;            }            UiDispatcher = Dispatcher.CurrentDispatcher;        }    }