页面过渡

PageTransitions are used to render a transition between two views, for example in a Carousel or TransitioningContentControl

The duration must be set before the transition is used and must be greater than 0. If not, you will get an error.

Build-In PageTransitions

CrossFade

The CrossFade fades out the current view and fades in the new view by animating the opacity.

XAML

<CrossFade Duration="0:00:00.500" />

C#

var transition = new CrossFade(TimeSpan.FromMilliseconds(500));

Source code

CrossFade.cs

Reference

CrossFade

PageSlide

The PageSlide slides the content either horizontally or vertically. You can specify the slide axis via the Orientation-property. The default value is Horizontal.

XAML

<PageSlide Duration="0:00:00.500" Orientation="Vertical" />

C#

var transition = new PageSlide(TimeSpan.FromMilliseconds(500), PageSlide.SlideAxis.Vertical);

Source code

PageSlide.cs

Reference

PageSlide

CompositePageTransition

The CompositePageTransition is used create a combined transition of several different transitions. The below sample creates a transition which slides the views diagonal (horizontally and vertically at the same time) and also fades the views out and in.

XAML

<CompositePageTransition>
    <CrossFade Duration="0:00:00.500" />
    <PageSlide Duration="0:00:00.500" Orientation="Horizontal" />
    <PageSlide Duration="0:00:00.500" Orientation="Vertical" />
</CompositePageTransition>

C#

var compositeTransition = new CompositePageTransition();
compositeTransition.PageTransitions.Add(new PageSlide(TimeSpan.FromMilliseconds(500), PageSlide.SlideAxis.Vertical));
compositeTransition.PageTransitions.Add(new PageSlide(TimeSpan.FromMilliseconds(500), PageSlide.SlideAxis.Horizontal));
compositeTransition.PageTransitions.Add(new CrossFade(TimeSpan.FromMilliseconds(500)));

Source code

CompositePageTransition.cs

Reference

CompositePageTransition

Custom PageTransitions

You can also create your own PageTransition by implementing the IPageTransition-interface.

The Interface has one member which you need to implement:

public Task Start(Visual? from, Visual? to, bool forward, CancellationToken cancellationToken)
{
    // Setup the transition here.
}

Example

Below is a sample which will shrink the old view and grow the new view in vertically direction.

public class CustomTransition : IPageTransition
{
    /// <summary>
    /// Initializes a new instance of the <see cref="CustomTransition"/> class.
    /// </summary>
    public CustomTransition()
    {
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="CustomTransition"/> class.
    /// </summary>
    /// <param name="duration">The duration of the animation.</param>
    public CustomTransition(TimeSpan duration)
    {
        Duration = duration;
    }

    /// <summary>
    /// Gets the duration of the animation.
    /// </summary>
    public TimeSpan Duration { get; set; }

    public async Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
    {
        if (cancellationToken.IsCancellationRequested)
        {
            return;
        }

        var tasks = new List<Task>();
        var parent = GetVisualParent(from, to);
        var scaleYProperty = ScaleTransform.ScaleYProperty;

        if (from != null)
        {
            var animation = new Animation
            {
                FillMode = FillMode.Forward,
                Children =
                {
                    new KeyFrame
                    {
                        Setters = { new Setter { Property = scaleYProperty, Value = 1d } },
                        Cue = new Cue(0d)
                    },
                    new KeyFrame
                    {
                        Setters =
                        {
                            new Setter
                            {
                                Property = scaleYProperty,
                                Value = 0d
                            }
                        },
                        Cue = new Cue(1d)
                    }
                },
                Duration = Duration
            };
            tasks.Add(animation.RunAsync(from, null, cancellationToken));
        }

        if (to != null)
        {
            to.IsVisible = true;
            var animation = new Animation
            {
                FillMode = FillMode.Forward,
                Children =
                {
                    new KeyFrame
                    {
                        Setters =
                        {
                            new Setter
                            {
                                Property = scaleYProperty,
                                Value = 0d
                            }
                        },
                        Cue = new Cue(0d)
                    },
                    new KeyFrame
                    {
                        Setters = { new Setter { Property = scaleYProperty, Value = 1d } },
                        Cue = new Cue(1d)
                    }
                },
                Duration = Duration
            };
            tasks.Add(animation.RunAsync(to, null, cancellationToken));
        }

        await Task.WhenAll(tasks);

        if (from != null && !cancellationToken.IsCancellationRequested)
        {
            from.IsVisible = false;
        }
    }

    /// <summary>
    /// Gets the common visual parent of the two control.
    /// </summary>
    /// <param name="from">The from control.</param>
    /// <param name="to">The to control.</param>
    /// <returns>The common parent.</returns>
    /// <exception cref="ArgumentException">
    /// The two controls do not share a common parent.
    /// </exception>
    /// <remarks>
    /// Any one of the parameters may be null, but not both.
    /// </remarks>
    private static IVisual GetVisualParent(IVisual? from, IVisual? to)
    {
        var p1 = (from ?? to)!.VisualParent;
        var p2 = (to ?? from)!.VisualParent;

        if (p1 != null && p2 != null && p1 != p2)
        {
            throw new ArgumentException("Controls for PageSlide must have same parent.");
        }

        return p1 ?? throw new InvalidOperationException("Cannot determine visual parent.");
    }
}

Custom Transition Example

Source code

IPageTransition.cs

Reference

IPageTransition