/// <summary>
        /// 引发 <see cref="E:System.Windows.FrameworkElement.Initialized"/> 事件。 每当在内部将 <see cref="P:System.Windows.FrameworkElement.IsInitialized"/> 设置为 true 时,都将调用此方法。
        /// </summary>
        /// <param name="e">包含事件数据的 <see cref="T:System.Windows.RoutedEventArgs"/>。</param>
        protected override async void OnInitialized(EventArgs e)
        {
            base.OnInitialized(e);

            if (!DesignerProperties.GetIsInDesignMode(this))
            {
                this.DataContext = this.ViewModel = new EditVideoViewModel();
                await this.ViewModel.LoadAsync();
            }
        }
        public void SendVideo(StorageFile file)
        {
            //threadpool
            if (file == null)
            {
                return;
            }

            if (VideoEditor == null)
            {
                VideoEditor = new EditVideoViewModel(ContinueSendVideo, GetUsernameHintsExternal, With);
                VideoEditor.SetVideoFile(file);
                NotifyOfPropertyChange(() => VideoEditor);
            }
            else
            {
                VideoEditor.SetVideoFile(file);

                BeginOnUIThread(() => VideoEditor.OpenEditor());
            }
        }