Question

我在WP7中创建了一个Scrollviewer，其中包含3个usercontrol，每个用户控件都作为其内容保存，XAML创建了UserControls。这很好用。此滚动查看器应该能够在这些项目之间滚动，但这使得用户无法滚动。因此，当单击其中一个内容中的项目时，滚动查看器将根据所选项目向左或向右滑动，并进入其中一个其他用户控件。我用一个中介来完成这个：

<Grid.Resources>
        <Storyboard x:Name="ItemAnimation">
            <DoubleAnimation x:Name="ItemAnimationContent"
                             Storyboard.TargetName="Mediator"
                             Storyboard.TargetProperty="ScrollableWidthMultiplier"/>
        </Storyboard>
</Grid.Resources> 
<ScrollViewer Name="ScrollableItemPanel" 
                  Grid.Row="2" 
                  Grid.RowSpan="3" 
                  Grid.ColumnSpan="3"
                  VerticalScrollBarVisibility="Disabled"
                  HorizontalScrollBarVisibility="Disabled">

        <StackPanel Orientation="Horizontal">
            <UserControl    Name="NewsListBoxControl" Width="480" />
            <UserControl    Name="DetailedItemControl" Width="480"/>            
            <UserControl    Name="ExternalBrowserItemControl" Width="480"/>
        </StackPanel>
    </ScrollViewer>

    <local:ScrollableItemAnimationMediator x:Name="Mediator" 
                                           ScrollViewer="{Binding ElementName=ScrollableItemPanel}"/>

基本上，这也可以正常工作，我可以在项目之间导航，并将内容作为用户控件加载到它们上面。但问题在于授予用户滚动的能力。在项目滚动之前，我将hittestvisibilty设置为true，并将horizontalscrollbarvisibility设置为可见。动画完成后，我想授予hittestvisibility并再次将horizontalscrollbarvisibility设置为Disabled。后者是问题所在：当我将horizontalscrollbarvisibility设置为Disabled时，scrollviewer会自动返回到stackpanel中三个项目中的第一个。我怎么能阻止这个？这是我用来滚动介体的代码：

private void CreateDetailedArticleItem( Dictionary<string, string> itemQuery )
    {
        _articleDetailPage.ItemQuery = itemQuery;
        DetailedItemControl.Content = _articleDetailPage as UserControl;
        Animate( _articleDetailPage, 0.0f, 0.5f, 250 );
    }

private void Animate( IContentControl control, float from, float to, double milliseconds )
    {                                                                                                                            
        //this eventhandler will fire when the animation has completed
        EventHandler handler = null;
        //we take away the User Input just for the moment, so that we can animate without the user interfering. Also, we make horizontalScroll Visible
        IsUserEnabled = false;

        //we then set the content of the animation. Where from will it move, towards where and in what duration?
        ItemAnimationContent.From = from;
        ItemAnimationContent.To = to;
        ItemAnimationContent.Duration = TimeSpan.FromMilliseconds( milliseconds );
        //we start the animation
        ItemAnimation.Begin( );

        //we tell the new control that it will appear soon, so it can load its main content
        control.ViewWillAppear( );
        //also, we tell the currentcontrol that it will disappear soon, so it can unload its content and eventhandlers and so on
        CurrentControl.ViewWillDisAppear( );

        //the handler is a delegate. This way, it becomes rather easy and clean to fire the completed event, without creating a strong reference ( well, actually,
        //we do create a strong reference, but as soon as it is fired, we remove it again, shhhh! ).
        handler = delegate( object sender, EventArgs e )
        {
            //as stated, we remove the eventlistener again, so it won't keep firing all the time
            ItemAnimation.Completed -= handler;

            //after the animation, we tell the new control that it is now in screen, and can start downloading its data
            control.ViewDidAppear( );
            //at the same time, the "current" control has fully moved out of view, so it can now fully unload all its content.
            CurrentControl.ViewDidDisAppear( );
            //now, all we have to do is to make sure that the next time an item is being loaded, the new content is spoken to, not the old one
            CurrentControl = control;

            //and finally, enable the users input again, and remove the horizontal scrollbarvisibility
            IsUserEnabled = true;                
        };            
        ItemAnimation.Completed += handler;
    }
 private bool IsUserEnabled
    {
        set
        {
            //when the user can control the scrollviewer, then the horizontal scrollvisibility is disabled, so that the user cannot move horizontally,
            //otherwise, so we only make it visible when the program needs to animate.
            ScrollableItemPanel.IsHitTestVisible = value;
            ScrollableItemPanel.HorizontalScrollBarVisibility = value ? ScrollBarVisibility.Disabled : ScrollBarVisibility.Visible;
        }
    }

我已经问过这个问题，然后把它视为已回答，因为我认为要回答，即使用ScrollbarVisibility.Hidden而不是ScrollbarVisibility.Disabled，只有滚动条可见性保持可见，用户仍然可以滚动。是否有一种本地方式来处理这个问题？

非常感谢任何帮助。格尔茨

Answer 1

不是打击本机控件的行为，而是使用自定义控件（包装其他控件）来操作项目的位置可能更容易，这些控件在不同的视觉状态之间激活（调整转换变换），具体取决于“选择“项目。

当滚动条可见性设置为禁用时，如何阻止Scrollviewer向后滚动？ WP7

1 个答案: