问CartesianChart与DateAxis和DateModel在X轴上的应用

EN

<UserControl x:Class="Wpf.Charts.SensorChart"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:lvc="clr-namespace:LiveCharts.Wpf;assembly=LiveCharts.Wpf"
             mc:Ignorable="d" 
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <lvc:CartesianChart Series="{Binding SeriesCollection}" LegendLocation="Left">
            <lvc:CartesianChart.AxisX>
                <lvc:DateAxis Title="Time"
                              InitialDateTime="{Binding InitialDateTime}"
                              Period="{Binding Period}"
                              SelectedWindow="{Binding SelectedWindow}"
                              LabelFormatter="{Binding Formatter}">
                </lvc:DateAxis>
            </lvc:CartesianChart.AxisX>
        </lvc:CartesianChart>
    </Grid>
</UserControl>

using LiveCharts;
using LiveCharts.Configurations;
using LiveCharts.Helpers;
using LiveCharts.Wpf;
using System;
using System.Windows.Controls;

namespace Wpf.Charts
{
    public partial class SensorChart : UserControl
    {
        public SeriesCollection SeriesCollection { get; set; }
        public DateTime InitialDateTime { get; set; }
        public PeriodUnits Period { get; set; }
        public IAxisWindow SelectedWindow { get; set; }
        private Func<double, string> Formatter { get; set; }

        public SensorChart()
        {
            InitializeComponent();
            this.SetChartModelValues();
            this.DataContext = this;
        }

        private void SetChartModelValues()
        {
            var dayConfig = Mappers.Xy<ChartModel>()
                   .X(dayModel => (double)dayModel.DateTime.Ticks / TimeSpan.FromSeconds(1).Ticks)
                   .Y(dayModel => dayModel.Value);

            DateTime now = DateTime.Now;
            now = new DateTime(now.Year, now.Month, now.Day, now.Hour, now.Minute, now.Second);

            this.SeriesCollection = new SeriesCollection(dayConfig)
            {
                new LineSeries()
                {
                    Values = new ChartValues<ChartModel>()
                    {
                        new ChartModel(now.AddSeconds(5), 3),
                        new ChartModel(now.AddSeconds(10), 6),
                        new ChartModel(now.AddSeconds(15), 8),
                        new ChartModel(now.AddSeconds(20), 4),
                        new ChartModel(now.AddSeconds(55), 7),
                        new ChartModel(now.AddSeconds(60), 2),
                        new ChartModel(now.AddSeconds(65), 6),
                        new ChartModel(now.AddSeconds(70), 8),
                        new ChartModel(now.AddSeconds(75), 4),
                        new ChartModel(now.AddSeconds(80), 7),
                        new ChartModel(now.AddSeconds(105), 3),
                        new ChartModel(now.AddSeconds(110), 6),
                        new ChartModel(now.AddSeconds(115), 8),
                        new ChartModel(now.AddSeconds(120), 4),
                        new ChartModel(now.AddSeconds(155), 7),
                        new ChartModel(now.AddSeconds(160), 2),
                        new ChartModel(now.AddSeconds(165), 6),
                        new ChartModel(now.AddSeconds(170), 8),
                        new ChartModel(now.AddSeconds(175), 4),
                        new ChartModel(now.AddSeconds(180), 7),
                    }
                }
            };
            //foreach ()

            this.InitialDateTime = now;
            this.Period = PeriodUnits.Seconds;
            this.SelectedWindow = new DateAxisWindows.FifteenSecondsAxisWindow();
            this.Formatter = this.DateLabelFormater;
        }

        private string DateLabelFormater(double value)
        {
            DateTime dateTime = new DateTime((long)(value * TimeSpan.FromSeconds(1).Ticks));
            return dateTime.ToString("HH:mm:ss");
        }
    }

    public class ChartModel
    {
        public DateTime DateTime { get; set; }
        public double Value { get; set; }

        public ChartModel(DateTime dateTime, double value)
        {
            this.DateTime = dateTime;
            this.Value = value;
        }
    }
}