windows phone app 添加启动页面介绍新功能

方案1： 利用 Panorama或者 pivotpage

1. 重写panorama page, 使其达到全屏

    public class PanoramaFullScreen : Panorama    {
        protected override System.Windows.Size MeasureOverride(System.Windows.Size availableSize)
        {
            availableSize.Width += 48;
            return base.MeasureOverride(availableSize);
        }
    }

2. 去掉 title 和 header，调整好margin

            <phone:PanoramaItem>
                <Grid Canvas.ZIndex="-1" Margin="-66,-40,-55,0" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Width="591">
                        <Image Stretch="Fill" Source="/Images/screen1.jpg" VerticalAlignment ="Stretch"
                          
                               HorizontalAlignment="Stretch" Margin="54,0,54,0"/>
                    </Grid>
            </phone:PanoramaItem>

3. 在codebehind 中控制页面跳转

 private TouchPoint first;
        private const int DetectRightGesture = 20;
        private int startIndex = 0;
        private readonly int endIndex;

        public WhatsNewView()
        {
            InitializeComponent();
            endIndex = MyStartScreen.Items.Count - 1;
            MyStartScreen.IsHitTestVisible = false;
            MyStartScreen.IsEnabled = false;
            Touch.FrameReported += Touch_FrameReported;
            TouchPanel.EnabledGestures = GestureType.HorizontalDrag;
        }

        private void Touch_FrameReported(object sender, TouchFrameEventArgs e)
        {
         
            try
            {
                TouchPoint mainTouch = e.GetPrimaryTouchPoint(this);
                if (mainTouch.Action == TouchAction.Down)
                    first = mainTouch;
                else if (mainTouch.Action == TouchAction.Up && TouchPanel.IsGestureAvailable)
                {
                    if (mainTouch.Position.X - first.Position.X < -DetectRightGesture)
                    {
                        if (startIndex < endIndex)
                        {
                            MyStartScreen.SlideToPage(startIndex + 1, SlideTransitionMode.SlideLeftFadeOut);
                            startIndex++;
                        }
                        else
                        {
                            NavigateToNextPage();
                        }
                    }
                    else if (mainTouch.Position.X - first.Position.X > DetectRightGesture)
                    {
                        if (startIndex > 0)
                        {
                            MyStartScreen.SlideToPage(startIndex - 1, SlideTransitionMode.SlideRightFadeOut);
                            startIndex--;
                        }
                    }
                }
            }
            catch
            {
            }
        }

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            NavigateToNextPage();
        }

        private void NavigateToNextPage()
        {
            NavigationService.Navigate(new Uri("/Views/LoginPage.xaml", UriKind.Relative));
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            while (NavigationService.BackStack.Any())
            {
                NavigationService.RemoveBackEntry();
            }
        }

4. 补充： 拓展panorama 方法，使其跳转附带动画

  public static void SlideToPage(this Panorama self, int item, SlideTransitionMode slideMode)
        {
            var slideTransition = new SlideTransition { };
            slideTransition.Mode = slideMode;
            ITransition transition = slideTransition.GetTransition(self);
            transition.Completed += delegate
            {
                self.DefaultItem = self.Items[item];
                transition.Stop();
            };

            transition.Begin();
        }

不足：

SlideTransitionMode SlideTransitionMode支持动画有限，一般达不到预期效果

方案2：

将所有图片水平排列，根据手势通过左右偏移来控制显示

 <Canvas>
            <StackPanel x:Name="Slider"
                        Canvas.Left="0"
                        Orientation="Horizontal">
                <Image Source="/Images/screen1.jpg"
                       Stretch ="UniformToFill"/>
                <Image Source="/Images/screen2.jpg"
                       Stretch ="UniformToFill" />
                <Image Source="/Images/screen3.jpg"
                       Stretch ="UniformToFill" />
            </StackPanel>
        </Canvas>

        public static readonly DependencyProperty SlidePageIndexProperty =
                 DependencyProperty.Register("SlidePageIndex", typeof(int), typeof(StartScreenView), null);

        public int SlidePageIndex
        {
            get { return (int)GetValue(SlidePageIndexProperty); }
            set { SetValue(SlidePageIndexProperty, value); }
        }

偏移量根据不同设备决定

 _uniformImageWidth = (int)Application.Current.Host.Content.ActualWidth;

手势控制

Touch.FrameReported += Touch_FrameReported;
            TouchPanel.EnabledGestures = GestureType.HorizontalDrag;

 private void Touch_FrameReported(object sender, TouchFrameEventArgs e)
        {
            try
            {
                TouchPoint mainTouch = e.GetPrimaryTouchPoint(this);
                if (mainTouch.Action == TouchAction.Down)
                    first = mainTouch;
                else if (mainTouch.Action == TouchAction.Up && TouchPanel.IsGestureAvailable)
                {
                    if (mainTouch.Position.X - first.Position.X < -DetectRightGesture)
                    {
                        if (SlidePageIndex == MaxSlidePageCount - 1)
                        {
                            NavigateToLoginPage();
                        }

                        SlidePageIndex++;
                        Slide();
                    }
                    else if (mainTouch.Position.X - first.Position.X > DetectRightGesture)
                    {
                        if (SlidePageIndex == 0) return;

                        SlidePageIndex--;

                        Slide();
                    }
                }
            }
            catch
            {
            }
        }

滑动逻辑

        private void Slide()
        {
            var storyboard = new Storyboard();
            var ani = new DoubleAnimation();

            ani.To = SlidePageIndex * -_uniformImageWidth;
            ani.Duration = TimeSpan.FromSeconds(1.0f);
            ani.EasingFunction = new ElasticEase() { EasingMode = EasingMode.EaseInOut, Oscillations = 0 };

            Storyboard.SetTarget(ani, this.Slider);
            Storyboard.SetTargetProperty(ani, new PropertyPath("(Canvas.Left)"));

            storyboard.Children.Add(ani);
            storyboard.Begin();
        }

此页面不可以通过back键导航

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            while (NavigationService.BackStack.Any())
            {
                NavigationService.RemoveBackEntry();
            }
        }