using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace InSituLaboratory.Views.Pages
{
    /// <summary>
    /// RelayView.xaml 的交互逻辑
    /// </summary>
    public partial class RelayView : UserControl
    {
        public RelayView()
        {
            InitializeComponent();
        }

        /// <summary>
        /// 支持鼠标滚轮上下滚动
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ScrollViewer_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
        {
            ScrollViewer viewer = sv;  //sv 为Scrollview的名字，在Xaml文件中定义。
            if (viewer == null) return;
            double num = Math.Abs((int)(e.Delta / 2));
            double offset = 0.0;
            if (e.Delta > 0)
            {
                offset = Math.Max((double)0.0, (double)(viewer.VerticalOffset - num));//viewer.VerticalOffset获取包含滚动内容的垂直偏移量的值。
            }
            else
            {
                offset = Math.Min(viewer.ScrollableHeight, viewer.VerticalOffset + num);
            }
            if (offset != viewer.VerticalOffset)
            {
                viewer.ScrollToVerticalOffset(offset);//将 ScrollViewer 内的内容滚动到指定的垂直偏移量位置。
                e.Handled = true;
            }
        }
    }
}