图表x轴显示优化

UIShare/UIViewModel/MonitorChannel.cs

@@ -1,5 +1,6 @@
 using OxyPlot.Series;
 using OxyPlot;
+using System;
 using System.Collections.Concurrent;
 using Prism.Mvvm;
 using NCalc;
@@ -52,7 +53,7 @@ namespace UIShare.UIViewModel
 
         // ===== 数据存储 =====
         /// <summary>所有采样数据点（线程安全），与 OxyPlot 无关</summary>
-        public ConcurrentQueue<(double Time, double RawValue, double DisplayValue)> DataPoints { get; } = new();
+        public ConcurrentQueue<(DateTime Time, double RawValue, double DisplayValue)> DataPoints { get; } = new();
 
         /// <summary>最大缓冲数据点数，超出则丢弃最旧的</summary>
         public int MaxBuffer { get; set; } = 5000;
@@ -67,7 +68,7 @@ namespace UIShare.UIViewModel
 
         // ===== 辅助方法 =====
         /// <summary>记录一个数据点：RawValue 经数学变换后得到 DisplayValue，一并入队</summary>
-        public void Record(double time, double rawValue)
+        public void Record(DateTime time, double rawValue)
         {
             double displayValue = rawValue;
 
@@ -82,7 +83,7 @@ namespace UIShare.UIViewModel
             // 如果正在显示，同步到 Series
             if (_series != null)
             {
-                _series.Points.Add(new DataPoint(time, displayValue));
+                _series.Points.Add(new DataPoint(time.ToOADate(), displayValue));
                 while (_series.Points.Count > 10000)
                 {
                     _series.Points.RemoveAt(0);