采用属性动画的方式。由于动画绑定时需要绑定依赖属性，由于ScrollViewer没有水平偏移和垂直偏移的依赖属性，所以需要通过附加属性的方式添加水平和垂直的依赖属性
public static class ScrollViewerBehavior { public static readonly DependencyProperty HorizontalOffsetProperty = DependencyProperty.RegisterAttached("HorizontalOffset",typeof(double),typeof(ScrollViewerBehavior),new UIPropertyMetadata(0.0,OnHorizontalOffsetChanged)); public static void SetHorizontalOffset(FrameworkElement target,double value) => target.SetValue(HorizontalOffsetProperty,value); public static double GetHorizontalOffset(FrameworkElement target) => (double)target.GetValue(HorizontalOffsetProperty); private static void OnHorizontalOffsetChanged(DependencyObject target,DependencyPropertyChangedEventArgs e) => (target as ScrollViewer)?.ScrollToHorizontalOffset((double)e.NewValue); public static readonly DependencyProperty VerticalOffsetProperty = DependencyProperty.RegisterAttached("VerticalOffset",OnVerticalOffsetChanged)); public static void SetVerticalOffset(FrameworkElement target,double value) => target.SetValue(VerticalOffsetProperty,value); public static double GetVerticalOffset(FrameworkElement target) => (double)target.GetValue(VerticalOffsetProperty); private static void OnVerticalOffsetChanged(DependencyObject target,DependencyPropertyChangedEventArgs e) => (target as ScrollViewer)?.ScrollToVerticalOffset((double)e.NewValue); }
xml 代码
<ScrollViewer HorizontalScrollBarVisibility="Disabled" Grid.Column="1" VerticalScrollBarVisibility="Hidden" HorizontalAlignment="Stretch" x:Name="ScrollViewertest" Margin="10,0" > <!--填充控件--> </ScrollViewer>
动画绑定，并开始动画
TimeSpan ts = new TimeSpan(0,0,25);//向下滚动耗时 double end = 20; //向下滚动距离 DoubleAnimation TopToButtomAnimation = new DoubleAnimation(); TopToButtomAnimation.EasingFunction = new SineEase { EasingMode = EasingMode.EaseInOut };//EasingMode：滚动方式 TopToButtomAnimation.From = 0; TopToButtomAnimation.To = end; TopToButtomAnimation.Duration = new Duration(ts); TopToButtomAnimation.AutoReverse = true; TopToButtomAnimation.SpeedRatio = 1;//滚动速率 storyboard.Duration = new Duration(TimeSpan.FromSeconds(50));//上下滚动总时长 storyboard.Children.Add(TopToButtomAnimation); Storyboard.SetTarget(TopToButtomAnimation,ScrollViewertest); Storyboard.SetTargetName(TopToButtomAnimation,ScrollViewertest.Name); Storyboard.SetTargetProperty(TopToButtomAnimation,new PropertyPath(ScrollViewerBehavior.VerticalOffsetProperty)); storyboard.RepeatBehavior = RepeatBehavior.Forever; storyboard.FillBehavior = FillBehavior.HoldEnd; storyboard.Begin();
List和DataGrid滚动都可以采取该方式，控制控件的ScrollViewer 进行滚动。
private childItem FindVisualChild<childItem>(DependencyObject obj) where childItem : DependencyObject { for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++) { DependencyObject child = VisualTreeHelper.GetChild(obj,i); if (child != null && child is childItem) return (childItem)child; else { childItem childOfChild = FindVisualChild<childItem>(child); if (childOfChild != null) return childOfChild; } } return null; }
