为了让用户有个更好的UI交互，可以增加自动淡出的消息弹窗，例如：网易云音乐UWP，切换播放模式时，出现的类似消息提示。

右键项目，添加用户控件

UserControlDemo.xaml:

<UserControl

    <UserControl.Resources>

        <Storyboard x:Name="story_Board" >

            <DoubleAnimationUsingKeyFrames Storyboard.TargetName="main_Grid"

                                Storyboard.TargetProperty="Opacity"

                                BeginTime="0:0:0">

                <SplineDoubleKeyFrame  KeyTime="00:00:00.00" Value="1"/>

                <SplineDoubleKeyFrame  KeyTime="00:00:00.400" Value="0.0"/>

            </DoubleAnimationUsingKeyFrames>

        </Storyboard>

    </UserControl.Resources>

    <Grid x:Name="main_Grid">

            <Border  CornerRadius="10"

                Background="Transparent"

                HorizontalAlignment="Center"

            VerticalAlignment="Center"

            Padding="15,5">

                    <TextBlock x:Name="showContent_textBlock" Margin="10,0,0,2" Foreground="WhiteSmoke"  FontSize="30"/>

            </Border>

    </Grid>

</UserControl>

UserControlDemo.xaml.cs:

public sealed partial class UserControlDemo : UserControl

    {

        private Popup popup;

        private string str;

        private TimeSpan showTime_tmr;

        public UserControlDemo()

        {

            this.InitializeComponent();

            popup = new Popup();

            popup.Child = this;

            MeasurePopupSize();

            this.Loaded += NotifyPopup_Loaded;

            this.Unloaded += NotifyPopup_Unloaded;

        }

        public VolumeContentDialog(string content, TimeSpan showTime) : this()

        {

            this.str = content;

            this.showTime_tmr = showTime;

        }

        public VolumeContentDialog(string content) : this(content, TimeSpan.FromSeconds(2))

        {

        }

        public void Show()

        {

            this.popup.IsOpen = true;

        }

        public void Hide()

        {

            this.popup.IsOpen = false;

        }

        private void MeasurePopupSize()

        {

            this.Width = ApplicationView.GetForCurrentView().VisibleBounds.Width;

            double marginTop = 0;

            if (ApiInformation.IsTypePresent("Windows.UI.ViewManagement.StatusBar"))

                marginTop = StatusBar.GetForCurrentView().OccludedRect.Height;

            this.Height = ApplicationView.GetForCurrentView().VisibleBounds.Height;

            this.Margin = new Thickness(0, marginTop, 0, 0);

        }

        private void NotifyPopup_Loaded(object sender, RoutedEventArgs e)

        {

            this.showContent_textBlock.Text = str;

            this.story_Board.BeginTime = this.showTime_tmr;

            this.story_Board.Begin();

            this.story_Board.Completed += storyBoard_Completed;

            ApplicationView.GetForCurrentView().VisibleBoundsChanged += NotifyPopup_VisibleBoundsChanged;

        }

        private void NotifyPopup_VisibleBoundsChanged(ApplicationView sender, object args)

        {

            MeasurePopupSize();

        }

        private void storyBoard_Completed(object sender, object e)

        {

            this.popup.IsOpen = false;

        }

        private void NotifyPopup_Unloaded(object sender, RoutedEventArgs e)

        {

            ApplicationView.GetForCurrentView().VisibleBoundsChanged -= NotifyPopup_VisibleBoundsChanged;

        }

    }

然后直接在MianPage.cs中实例化引用就可以了。

MainPage.xaml.cs:

UserControlDemo demo = new UserControlDemo("Demo");

demo.Show();