WPF ScrollViewer控件 触屏滑动

备份下    原文 https://www.cnblogs.com/webenh/p/18207292

<ScrollViewer x:Name="scroll" TouchDown="mScrollViewer_TouchDown" TouchMove="mScrollViewer_TouchMove" TouchUp="mScrollViewer_TouchUp">
</ScrollViewer>

double mPointY;//触摸点的Y坐标
double mOffsetY;//滚动条当前位置
bool mIsTouch = false;//是否触摸

//触摸事件
private void mScrollViewer_TouchDown(object sender, TouchEventArgs e)
{
    mIsTouch = true;//正在触摸
    mOffsetY = this.scroll.VerticalOffset;//获取ScrollViewer滚动条当前位置
    TouchPoint point = e.GetTouchPoint(scroll);//获取相对于ScrollViewer的触摸点位置
    mPointY = point.Position.Y;//触摸点的Y坐标
}

//触摸移动事件
private void mScrollViewer_TouchMove(object sender, TouchEventArgs e)
{
    if (mIsTouch == true)//如果正在触摸
    {
        TouchPoint point = e.GetTouchPoint(scroll);//获取相对于ScrollViewer的触摸点位置
        double DiffOffset = point.Position.Y - mPointY;//计算相对位置
        this.scroll.ScrollToVerticalOffset(mOffsetY - DiffOffset);//ScrollViewer滚动到指定位置
    }
}

//触摸结束事件
private void mScrollViewer_TouchUp(object sender, TouchEventArgs e)
{
    mIsTouch = false;//触摸结束
}