ee649090(v=vs.110).aspx

win8支持多点触摸技术，而我们在屏幕上所做的各种操作，也最终转换为输入

http://code.msdn.microsoft.com/windowsapps/Input-3dff271b

http://msdn.microsoft.com/zh-cn/library/windows/apps/xaml/hh465387#using_manipulation_events

在window runtime上响应触屏事件的方法分为两类：单点和多点。下面分别介绍：

鼠标操作事件：

PointerWheelChanged ：鼠标滚轮转动时发生

PointerPressed ：鼠标点击下去的时候即触发事件。 PointerReleased ：鼠标点击下去的时候释放鼠标时触发事件。 PointerMoved ：鼠标在有效范围之内移动之时触发事件。 PointerEntered ：鼠标进入有效范围之时触发一次。 PointerExited ：鼠标退出有效范围之时触发事件。

这些事件的参数都是 PointerRoutedEventArgs

多点事件包括：

ManipulationStarting ManipulationStarted ManipulationInertiaStarting ManipulationDelta ManipulationCompleted

当多点操作时，一般先触发 ManipulationStarted 事件，然后是一连串的ManipulationDelta事件触发，最后是ManipulationCompleted事件.

注意实现多点操作的时候要设置多点操作对象的 ManipulationMode 属性

http://msdn.microsoft.com/zh-cn/library/windows/apps/xaml/hh465387#using_manipulation_events

下面看一个示例：

按 Ctrl+C 复制代码

<Page

    x:Class="PhotoDemo.MainPage"

    IsTabStop="false"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    xmlns:local="using:PhotoDemo"

    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

    mc:Ignorable="d">

<Grid x:Name="LayoutRoot" Background="White">

        <TextBlock x:Name="OpeningMessage" Text="Tap here to open a photo" Foreground="#FF4080E0" FontSize="48" HorizontalAlignment="Center" VerticalAlignment="Center"/>

        <Grid RenderTransformOrigin="0.5,0.5">

            <Grid.RenderTransform>

                <CompositeTransform x:Name="PhotoTransform" />

            </Grid.RenderTransform>

            <Image x:Name="Photo" Margin="20" Width="600"/>

        </Grid>

    </Grid>

</Page>

按 Ctrl+C 复制代码

按 Ctrl+C 复制代码

/// <summary>

    /// An empty page that can be used on its own or navigated to within a Frame.

    /// </summary>

    public sealed partial class MainPage : Page

    {

        public MainPage()

        {

            this.InitializeComponent();

            this.LayoutRoot.DoubleTapped += LayoutRoot_DoubleTapped;

            this.OpeningMessage.Tapped += OpeningMessage_Tapped;

            this.Photo.Tapped+=Photo_Tapped;

            this.Photo.ManipulationMode=ManipulationModes.All;

            this.Photo.ManipulationDelta+=Photo_ManipulationDelta;

        }

        /// <summary>

        /// Invoked when this page is about to be displayed in a Frame.

        /// </summary>

        /// <param name="e">Event data that describes how this page was reached.  The Parameter

        /// property is typically used to configure the page.</param>

        protected override void OnNavigatedTo(NavigationEventArgs e)

        {

        }

        async private void OpeningMessage_Tapped(object sender, TappedRoutedEventArgs e)

        {

            // Display a FileOpenPicker and allow the user to select a photo

            var picker = new FileOpenPicker();

            picker.FileTypeFilter.Add(".jpg");

            picker.FileTypeFilter.Add(".png");

            picker.FileTypeFilter.Add(".bmp");

            picker.FileTypeFilter.Add(".gif");

            picker.ViewMode = PickerViewMode.Thumbnail;

            picker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;

            var file = await picker.PickSingleFileAsync();

            if (file != null)

            {

                var stream = await file.OpenAsync(FileAccessMode.Read);

                // Wrap a WriteableBitmap around the selected photo and display it

                WriteableBitmap bitmap = new WriteableBitmap(1, 1);

                bitmap.SetSource(stream);

                Photo.Source = bitmap;

                // Reset the CompositeTransform

                PhotoTransform.TranslateX = PhotoTransform.TranslateY = 0.0;

                PhotoTransform.ScaleX = PhotoTransform.ScaleY = 1.0;

                // Hide the "Tap here" message in case it hasn't been removed already

                OpeningMessage.Visibility = Visibility.Collapsed;

            }

        }

        private void Photo_ManipulationDelta(object sender, ManipulationDeltaRoutedEventArgs e)

        {

            // Translate the photo

            PhotoTransform.TranslateX += e.Delta.Translation.X;

            PhotoTransform.TranslateY += e.Delta.Translation.Y;

            // Scale the photo

            PhotoTransform.ScaleX *= e.Delta.Scale;

            PhotoTransform.ScaleY *= e.Delta.Scale;

            // Constrain scale factor

            PhotoTransform.ScaleX = Math.Min(PhotoTransform.ScaleX, 4.0);

            PhotoTransform.ScaleY = Math.Min(PhotoTransform.ScaleY, 4.0);

            PhotoTransform.ScaleX = Math.Max(PhotoTransform.ScaleX, 1.0);

            PhotoTransform.ScaleY = Math.Max(PhotoTransform.ScaleY, 1.0);

        }

        private void LayoutRoot_DoubleTapped(object sender, DoubleTappedRoutedEventArgs e)

        {

            // Reset the CompositeTransform

            PhotoTransform.TranslateX = PhotoTransform.TranslateY = 0.0;

            PhotoTransform.ScaleX = PhotoTransform.ScaleY = 1.0;

        }

        private void Photo_Tapped(object sender, TappedRoutedEventArgs e)

        {

        }

    }

按 Ctrl+C 复制代码