触摸屏实现触摸垂直滑动效果

 <ScrollViewer x:Name="scrollViewer" Grid.Row="1" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Visible">
            <TextBlock xml:space="preserve" Grid.Row="1" Width="820" x:Name="TBContent" Style="{StaticResource ContentTextBlock}" TouchDown="TBContent_TouchDown" TouchMove="TBContent_TouchMove"/>
        </ScrollViewer>

前端用一个ScrollViewer 加文本 使用TouchDown 和 touchMove事件

后台事件代码：

 double downYPosition = 0; //记录当前触摸位置
        private void TBContent_TouchDown(object sender, System.Windows.Input.TouchEventArgs e)
        {
            var position = e.GetTouchPoint(this);
            downYPosition= position.Position.Y;
        }

        private void TBContent_TouchMove(object sender, System.Windows.Input.TouchEventArgs e)
        {
            var position = e.GetTouchPoint(this);
            var y = position.Position.Y;
            var disY = y - downYPosition;

            var offset = scrollViewer.VerticalOffset;
            var curOffset = offset - disY;

            if (curOffset <= 0)
            {
                curOffset = 0;
            }
            else if(curOffset> scrollViewer.ExtentHeight)
            {
                curOffset = scrollViewer.ExtentHeight;
            }

            scrollViewer.ScrollToVerticalOffset(curOffset);

            downYPosition = y;
        }