WPF次线程激活主线程UI相应

        void UIAction(Action action)        {            System.Threading.SynchronizationContext.SetSynchronizationContext(new System.Windows.Threading.DispatcherSynchronizationContext(App.Current.Dispatcher));            System.Threading.SynchronizationContext.Current.Post(_ => action(), null);        }

直接调用即可

UIAction(() =>            {                            txtTip.Text = str;                           }                );