WPF DocumentViewer在XPS文档的触摸屏上启用滚动

Question

在WPF应用程序的文档视图控制器中显示XPS文档时，它不允许您在触摸启用的平板上滚动其内容，只是将手指移到屏幕上。

相反，它选择文本。在启用触摸的设备上滚动的唯一方法是使用垂直滚动条。

是否有一种方法可以通过在内容本身上移动手指而不是在垂直滚动栏上来启用触摸滚动？

通过覆盖一些样式，我可以防止文本选择，但仍然不允许我滚动。（https://stackoverflow.com/a/415155/187650）

Answer 1

我遇到了相同的问题，我做了一个解决方案，并且可以很好地工作。

我做了一个自己的XPS文档类，以动态设置URI：

public class ManualXpsDocument : XpsDocument
{
    private const string _uriOfDoc= "...\path.xps";
    public ManualXpsDocument(FileAccess fileAccess) : base(_uriOfDoc, fileAccess)
    {
    }
}

这是窗口的XAML部分（或控制）：

  <Grid.Resources>
        <ObjectDataProvider x:Key="myDataSource" MethodName="GetFixedDocumentSequence"
                            ObjectType="{x:Type manual:ManualXpsDocument}">
            <ObjectDataProvider.ConstructorParameters>
                <io:FileAccess>Read</io:FileAccess>
            </ObjectDataProvider.ConstructorParameters>
        </ObjectDataProvider>
    </Grid.Resources>
    <DocumentViewer  x:Name="Viewer" Document="{Binding Source={StaticResource myDataSource}}">
        <DocumentViewer.Resources>
            <Style TargetType="ToolBar">
                <Setter Property="Visibility" Value="Collapsed" />
            </Style>
            <Style TargetType="{x:Type ContentControl}">
                <Setter Property="Visibility" Value="Collapsed" />
            </Style>
        </DocumentViewer.Resources>
        <DocumentViewer.Style>
            <Style TargetType="{x:Type DocumentViewer}">
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type DocumentViewer}">
                            <controls:CustomScrollViewer x:Name="PART_ContentHost">
                                <controls:CustomScrollViewer.Style>
                                    <Style TargetType="{x:Type ScrollViewer}">
                                        <Setter Property="Focusable" Value="false" />
                                        <Setter Property="IsDeferredScrollingEnabled" Value="True" />
                                        <Setter Property="Template">
                                            <Setter.Value>
                                                <ControlTemplate TargetType="{x:Type ScrollViewer}">
                                                    <Border BorderBrush="#00000000"
                                                        BorderThickness="0,2,0,0">
                                                        <Grid Background="{TemplateBinding Background}"
                                                             SnapsToDevicePixels="true">
                                                            <Grid.ColumnDefinitions>
                                                                <ColumnDefinition Width="*" />
                                                                <ColumnDefinition Width="Auto" />
                                                            </Grid.ColumnDefinitions>
                                                            <Grid.RowDefinitions>
                                                                <RowDefinition Height="*" />
                                                                <RowDefinition Height="Auto" />
                                                            </Grid.RowDefinitions>
                                                            <ScrollContentPresenter Name="PART_ScrollContentPresenter"
                                                                                        ScrollViewer.IsDeferredScrollingEnabled="True"
                                                                                        KeyboardNavigation.DirectionalNavigation="Local"
                                                                                        CanContentScroll="True" 
                                                                                        SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />

                                                            <controls:CustomScrollBar Name="PART_VerticalScrollBar"
                                                                                      Style="{DynamicResource ScrollBar}"
                                                                                      Grid.Column="1"
                                                                                      Value="{TemplateBinding VerticalOffset}"
                                                                                      Maximum="{TemplateBinding ScrollableHeight}"
                                                                                      ViewportSize="{TemplateBinding ViewportHeight}"
                                                                                      Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" />
                                                            <controls:CustomScrollBar Name="PART_HorizontalScrollBar"
                                                                                      Grid.Row="1"
                                                                                      Grid.ColumnSpan="2"
                                                                                      Style="{DynamicResource ScrollBar}"
                                                                                      Orientation="Horizontal"       
                                                                                      Value="{TemplateBinding HorizontalOffset}"
                                                                                      Maximum="{TemplateBinding ScrollableWidth}"
                                                                                      ViewportSize="{TemplateBinding ViewportWidth}"
                                                                                      Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" />
                                                        </Grid>
                                                    </Border>
                                                </ControlTemplate>
                                            </Setter.Value>
                                        </Setter>
                                    </Style>
                                </controls:CustomScrollViewer.Style>                                 
                            </controls:CustomScrollViewer>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </DocumentViewer.Style>
    </DocumentViewer>

这是窗口的XAML.CS部分（或控制）：

    public ctor()
    {
        InitializeComponent();
        PreviewTouchMove += ScrollingHandler;
    }
    private void ScrollingHandler(object sender, TouchEventArgs e)
    {
        TouchPoint tp = e.GetTouchPoint(Viewer);
        if (tp.Action == TouchAction.Move)
        {
            //_scrollingInt is not necessary but Move procedure of Viewer has const value to scroll and the optimalization is recommended. 
            if (_lastYPosition > tp.Position.Y + _scrollingInt)
            {
                Viewer.MoveDown();
                _lastYPosition = tp.Position.Y;
            }  
            else if (_lastYPosition < tp.Position.Y - _scrollingInt)
            {
                Viewer.MoveUp();
                _lastYPosition = tp.Position.Y;
            }
        }
        // Viewer.IsHitTestVisible = false; this setting can disable the selection too,but if you use this, the hyperlinks won't work too.
        Viewer.GetType().GetProperty("IsSelectionEnabled", BindingFlags.Instance | BindingFlags.NonPublic).SetValue(Viewer, false, null);
        //set false "IsSelectionEnabled" "hidden" property instead of Viewer.IsHitTestVisible = false, because the hyperlinks will work too. 
        e.Handled = true;
    }

ScrollingHandler方法解决了问题。此过程进行文档查看器的滚动并禁用选择，但超链接功能仍然可用。