diff --git a/Bin/SunnyUI.Demo.exe b/Bin/SunnyUI.Demo.exe
index 6e42662f..37d861fe 100644
Binary files a/Bin/SunnyUI.Demo.exe and b/Bin/SunnyUI.Demo.exe differ
diff --git a/Bin/SunnyUI.dll b/Bin/SunnyUI.dll
index 129759dd..4edfd172 100644
Binary files a/Bin/SunnyUI.dll and b/Bin/SunnyUI.dll differ
diff --git a/Bin/SunnyUI.pdb b/Bin/SunnyUI.pdb
index 2de7fe51..e48cd7b0 100644
Binary files a/Bin/SunnyUI.pdb and b/Bin/SunnyUI.pdb differ
diff --git a/SunnyUI.Demo/Charts/FLineChart.Designer.cs b/SunnyUI.Demo/Charts/FLineChart.Designer.cs
index d06e2037..e5d30ffe 100644
--- a/SunnyUI.Demo/Charts/FLineChart.Designer.cs
+++ b/SunnyUI.Demo/Charts/FLineChart.Designer.cs
@@ -33,7 +33,7 @@
             this.uiImageButton2 = new Sunny.UI.UIImageButton();
             this.uiImageButton1 = new Sunny.UI.UIImageButton();
             this.uiLine1 = new Sunny.UI.UILine();
-            this.uiLineChart1 = new Sunny.UI.UILineChart();
+            this.LineChart = new Sunny.UI.UILineChart();
             this.PagePanel.SuspendLayout();
             ((System.ComponentModel.ISupportInitialize)(this.uiImageButton3)).BeginInit();
             ((System.ComponentModel.ISupportInitialize)(this.uiImageButton2)).BeginInit();
@@ -47,7 +47,7 @@
             this.PagePanel.Controls.Add(this.uiImageButton2);
             this.PagePanel.Controls.Add(this.uiImageButton1);
             this.PagePanel.Controls.Add(this.uiLine1);
-            this.PagePanel.Controls.Add(this.uiLineChart1);
+            this.PagePanel.Controls.Add(this.LineChart);
             this.PagePanel.Size = new System.Drawing.Size(800, 539);
             // 
             // uiSymbolButton1
@@ -62,6 +62,7 @@
             this.uiSymbolButton1.Symbol = 61952;
             this.uiSymbolButton1.TabIndex = 34;
             this.uiSymbolButton1.Text = "数据";
+            this.uiSymbolButton1.Click += new System.EventHandler(this.uiSymbolButton1_Click);
             // 
             // uiImageButton3
             // 
@@ -113,18 +114,19 @@
             this.uiLine1.Text = "UIBarChart";
             this.uiLine1.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
             // 
-            // uiLineChart1
+            // LineChart
             // 
-            this.uiLineChart1.FillColor = System.Drawing.Color.FromArgb(((int)(((byte)(244)))), ((int)(((byte)(244)))), ((int)(((byte)(244)))));
-            this.uiLineChart1.Font = new System.Drawing.Font("微软雅黑", 12F);
-            this.uiLineChart1.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(54)))), ((int)(((byte)(54)))), ((int)(((byte)(54)))));
-            this.uiLineChart1.Location = new System.Drawing.Point(30, 48);
-            this.uiLineChart1.MinimumSize = new System.Drawing.Size(1, 1);
-            this.uiLineChart1.Name = "uiLineChart1";
-            this.uiLineChart1.Option = null;
-            this.uiLineChart1.Size = new System.Drawing.Size(670, 400);
-            this.uiLineChart1.TabIndex = 35;
-            this.uiLineChart1.Text = "uiLineChart1";
+            this.LineChart.FillColor = System.Drawing.Color.FromArgb(((int)(((byte)(244)))), ((int)(((byte)(244)))), ((int)(((byte)(244)))));
+            this.LineChart.Font = new System.Drawing.Font("微软雅黑", 12F);
+            this.LineChart.ForeColor = System.Drawing.Color.FromArgb(((int)(((byte)(54)))), ((int)(((byte)(54)))), ((int)(((byte)(54)))));
+            this.LineChart.Location = new System.Drawing.Point(30, 48);
+            this.LineChart.MinimumSize = new System.Drawing.Size(1, 1);
+            this.LineChart.Name = "LineChart";
+            this.LineChart.Option = null;
+            this.LineChart.Size = new System.Drawing.Size(670, 400);
+            this.LineChart.TabIndex = 35;
+            this.LineChart.Text = "uiLineChart1";
+            this.LineChart.PointValue += new Sunny.UI.UILineChart.OnPointValue(this.LineChart_PointValue);
             // 
             // FLineChart
             // 
@@ -149,6 +151,6 @@
         private UIImageButton uiImageButton2;
         private UIImageButton uiImageButton1;
         private UILine uiLine1;
-        private UILineChart uiLineChart1;
+        private UILineChart LineChart;
     }
 }
\ No newline at end of file
diff --git a/SunnyUI.Demo/Charts/FLineChart.cs b/SunnyUI.Demo/Charts/FLineChart.cs
index 2bf080ab..90066bae 100644
--- a/SunnyUI.Demo/Charts/FLineChart.cs
+++ b/SunnyUI.Demo/Charts/FLineChart.cs
@@ -1,4 +1,8 @@
-namespace Sunny.UI.Demo.Charts
+using System;
+using System.Drawing;
+using System.Text;
+
+namespace Sunny.UI.Demo.Charts
 {
     public partial class FLineChart : UITitlePage
     {
@@ -6,5 +10,63 @@
         {
             InitializeComponent();
         }
+
+        private void uiSymbolButton1_Click(object sender, System.EventArgs e)
+        {
+            UILineOption option = new UILineOption();
+            option.Title = new UITitle();
+            option.Title.Text = "SunnyUI";
+            option.Title.SubText = "LineChart";
+
+            option.XAxisType = UIAxisType.Time;
+
+            var series = option.AddSeries(new UILineSeries("Line1"));
+            DateTime dt = new DateTime(2020, 10, 4);
+            series.Add(dt.AddHours(0), 1.2);
+            series.Add(dt.AddHours(0.1), 2.2);
+            series.Add(dt.AddHours(0.2), 3.2);
+            series.Add(dt.AddHours(0.3), 4.2);
+            series.Add(dt.AddHours(0.4), 3.2);
+            series.Add(dt.AddHours(0.5), 2.2);
+            series.Symbol = UILinePointSymbol.Square;
+            series.SymbolSize = 4;
+            series.SymbolLineWidth = 2;
+            series.SymbolColor = Color.Red;
+
+            series = option.AddSeries(new UILineSeries("Line2"));
+            series.Add(dt.AddHours(0.3), 3.3);
+            series.Add(dt.AddHours(0.4), 2.3);
+            series.Add(dt.AddHours(0.5), 2.3);
+            series.Add(dt.AddHours(0.6), 1.3);
+            series.Add(dt.AddHours(0.7), 2.3);
+            series.Add(dt.AddHours(0.8), 4.3);
+            series.Symbol = UILinePointSymbol.Star;
+            series.SymbolSize = 4;
+            series.SymbolLineWidth = 2;
+            series.SymbolColor = Color.Red;
+            series.Smooth = true;
+
+            // option.XAxis.Min = new DateTimeInt64(dt.AddDays(-1));
+            // option.XAxis.Max = new DateTimeInt64(dt.AddDays(1));
+            // option.XAxis.MaxAuto = false;
+            // option.XAxis.MinAuto = false;
+
+            option.XAxis.Name = "数值";
+            option.YAxis.Name = "数值";
+
+            LineChart.SetOption(option);
+        }
+
+        private void LineChart_PointValue(object sender, System.Collections.Generic.List<UILineSelectPoint> points)
+        {
+            StringBuilder sb = new StringBuilder();
+            foreach (var point in points)
+            {
+                sb.Append(point.Name + ", " + point.Index + ", " + point.X + ", " + point.Y);
+                sb.Append('\n');
+            }
+
+            Console.WriteLine(sb.ToString());
+        }
     }
 }
diff --git a/SunnyUI/Charts/UIBarChart.cs b/SunnyUI/Charts/UIBarChart.cs
index 1cf3d2af..b7d833ef 100644
--- a/SunnyUI/Charts/UIBarChart.cs
+++ b/SunnyUI/Charts/UIBarChart.cs
@@ -62,8 +62,11 @@ namespace Sunny.UI
             double max = double.MinValue;
             foreach (var series in BarOption.Series)
             {
-                min = Math.Min(min, series.Data.Min());
-                max = Math.Max(max, series.Data.Max());
+                if (series.Data.Count > 0)
+                {
+                    min = Math.Min(min, series.Data.Min());
+                    max = Math.Max(max, series.Data.Max());
+                }
             }
 
             if (min > 0 && max > 0 && !BarOption.YAxis.Scale) min = 0;
diff --git a/SunnyUI/Charts/UIBarChartOption.cs b/SunnyUI/Charts/UIBarChartOption.cs
index b5343016..d22bb981 100644
--- a/SunnyUI/Charts/UIBarChartOption.cs
+++ b/SunnyUI/Charts/UIBarChartOption.cs
@@ -159,15 +159,31 @@ namespace Sunny.UI
 
         public event DoFormatter Formatter;
 
-        public string GetLabel(double value, int index)
+        public string GetLabel(double value, int index, UIAxisType axisType = UIAxisType.Value)
         {
-            return Formatter != null ? Formatter?.Invoke(value, index) : value.ToString("F" + DecimalCount);
+            switch (axisType)
+            {
+                case UIAxisType.Value:
+                    return Formatter != null ? Formatter?.Invoke(value, index) : value.ToString("F" + DecimalCount);
+                case UIAxisType.Time:
+                    DateTimeInt64 dt = new DateTimeInt64((long)value);
+                    return Formatter != null ? Formatter?.Invoke(dt, index) : (DateTimeFormat.IsNullOrEmpty() ? dt.ToString() : dt.ToString(DateTimeFormat));
+                case UIAxisType.Category:
+                    return Formatter != null ? Formatter?.Invoke(value, index) : value.ToString("F0");
+            }
+
+            return value.ToString("F2");
         }
 
         /// <summary>
         /// 小数位个数，Formatter不为空时以Formatter为准
         /// </summary>
         public int DecimalCount { get; set; } = 0;
+
+        /// <summary>
+        /// 日期格式化字符串，Formatter不为空时以Formatter为准
+        /// </summary>
+        public string DateTimeFormat { get; set; } = "HH:mm";
     }
 
     public class UIAxisTick
diff --git a/SunnyUI/Charts/UILineChart.cs b/SunnyUI/Charts/UILineChart.cs
index dbf6a54a..88103548 100644
--- a/SunnyUI/Charts/UILineChart.cs
+++ b/SunnyUI/Charts/UILineChart.cs
@@ -1,9 +1,10 @@
-using Sunny.UI.Charts;
-using System;
+using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Drawing;
 using System.Drawing.Drawing2D;
 using System.Linq;
+using System.Windows.Forms;
 
 namespace Sunny.UI
 {
@@ -42,13 +43,13 @@ namespace Sunny.UI
 
             foreach (var series in LineOption.Series.Values)
             {
-                series.Points.Clear();
+                series.ClearPoints();
 
                 for (int i = 0; i < series.XData.Count; i++)
                 {
-                    float x = (float)(series.XData[i] - XAxisStart) * 1.0f * DrawSize.Width / (XAxisEnd - XAxisStart);
-                    float y = (float)(series.YData[i] - YAxisStart) * 1.0f * DrawSize.Height / (YAxisEnd - YAxisStart);
-                    series.Points.Add(new PointF(DrawOrigin.X + x, DrawOrigin.Y - y));
+                    float x = (float)((series.XData[i] - XAxisStart * XAxisInterval) * 1.0f * DrawSize.Width / XAxisInterval / (XAxisEnd - XAxisStart));
+                    float y = (float)((series.YData[i] - YAxisStart * YAxisInterval) * 1.0f * DrawSize.Height / YAxisInterval / (YAxisEnd - YAxisStart));
+                    series.AddPoint(new PointF(DrawOrigin.X + x, DrawOrigin.Y - y));
                 }
             }
 
@@ -62,8 +63,11 @@ namespace Sunny.UI
             double max = double.MinValue;
             foreach (var series in LineOption.Series.Values)
             {
-                min = Math.Min(min, series.YData.Min());
-                max = Math.Max(max, series.YData.Max());
+                if (series.DataCount > 0)
+                {
+                    min = Math.Min(min, series.YData.Min());
+                    max = Math.Max(max, series.YData.Max());
+                }
             }
 
             if (min > 0 && max > 0 && !LineOption.YAxis.Scale) min = 0;
@@ -93,8 +97,8 @@ namespace Sunny.UI
                 max = Math.Max(max, series.XData.Max());
             }
 
-            if (min > 0 && max > 0 && !LineOption.XAxis.Scale) min = 0;
-            if (min < 0 && max < 0 && !LineOption.XAxis.Scale) max = 0;
+            if (min > 0 && max > 0 && !LineOption.XAxis.Scale && LineOption.XAxisType == UIAxisType.Value) min = 0;
+            if (min < 0 && max < 0 && !LineOption.XAxis.Scale && LineOption.XAxisType == UIAxisType.Value) max = 0;
             if (!LineOption.XAxis.MaxAuto) max = LineOption.XAxis.Max;
             if (!LineOption.XAxis.MinAuto) min = LineOption.XAxis.Min;
 
@@ -104,12 +108,23 @@ namespace Sunny.UI
                 min = 0;
             }
 
-            UIChartHelper.CalcDegreeScale(min, max, LineOption.XAxis.SplitNumber,
-                out int startX, out int endX, out double intervalX);
+            if (LineOption.XAxisType == UIAxisType.Value || LineOption.XAxisType == UIAxisType.Category)
+            {
+                UIChartHelper.CalcDegreeScale(min, max, LineOption.XAxis.SplitNumber,
+                   out int startX, out int endX, out double intervalX);
+                XAxisStart = startX;
+                XAxisEnd = endX;
+                XAxisInterval = intervalX;
+            }
 
-            XAxisStart = startX;
-            XAxisEnd = endX;
-            XAxisInterval = intervalX;
+            if (LineOption.XAxisType == UIAxisType.Time)
+            {
+                UIChartHelper.CalcDateTimeDegreeScale(min, max, LineOption.XAxis.SplitNumber,
+                    out int startX, out int endX, out double intervalX);
+                XAxisStart = startX;
+                XAxisEnd = endX;
+                XAxisInterval = intervalX;
+            }
         }
 
         [Browsable(false)]
@@ -131,15 +146,31 @@ namespace Sunny.UI
             option.Title.Text = "SunnyUI";
             option.Title.SubText = "LineChart";
 
-            option.AddSeries(new UILineSeries("Line"));
-            option.AddData("Line", 0, 1);
-            option.AddData("Line", 1, 2);
-            option.AddData("Line", 2, 3);
-            option.AddData("Line", 3, 4);
-            option.AddData("Line", 4, 3);
-            option.AddData("Line", 5, 2);
+            var series = option.AddSeries(new UILineSeries("Line1"));
+            series.Add(0, 1.2);
+            series.Add(1.1, 2.2);
+            series.Add(2.2, 3.2);
+            series.Add(3.3, 4.2);
+            series.Add(4.4, 3.2);
+            series.Add(5.5, 2.2);
+            series.Symbol = UILinePointSymbol.Square;
+            series.SymbolSize = 4;
+            series.SymbolLineWidth = 1;
+            series.SymbolColor = Color.Red;
 
-            option.XAxis.Name = "日期";
+            series = option.AddSeries(new UILineSeries("Line2"));
+            series.Add(0.3, 3.3);
+            series.Add(1.3, 2.3);
+            series.Add(2.3, 2.3);
+            series.Add(3.3, 1.3);
+            series.Add(4.3, 2.3);
+            series.Add(5.3, 4.3);
+            series.Symbol = UILinePointSymbol.Plus;
+            series.SymbolSize = 4;
+            series.SymbolLineWidth = 1;
+            series.SymbolColor = Color.Red;
+
+            option.XAxis.Name = "数值";
             option.YAxis.Name = "数值";
 
             emptyOption = option;
@@ -204,7 +235,7 @@ namespace Sunny.UI
                 float wmax = 0;
                 for (int i = XAxisStart; i <= XAxisEnd; i++)
                 {
-                    string label = LineOption.XAxis.AxisLabel.GetLabel(i * XAxisInterval, idx);
+                    string label = LineOption.XAxis.AxisLabel.GetLabel(i * XAxisInterval, idx, LineOption.XAxisType);
                     SizeF sf = g.MeasureString(label, SubFont);
                     wmax = Math.Max(wmax, sf.Width);
                     g.DrawString(label, SubFont, ChartStyle.ForeColor, start - sf.Width / 2.0f,
@@ -277,10 +308,80 @@ namespace Sunny.UI
                 Color color = series.Color;
                 if (!series.CustomColor) color = ChartStyle.GetColor(idx);
 
-                if (series.Smooth)
-                    g.DrawCurve(color, series.Points.ToArray(), true);
-                else
-                    g.DrawLines(series.Color, series.Points.ToArray(), true);
+                using (Pen pen = new Pen(color, series.Width))
+                {
+                    g.SetHighQuality();
+                    if (series.Smooth)
+                        g.DrawCurve(pen, series.Points.ToArray());
+                    else
+                        g.DrawLines(pen, series.Points.ToArray());
+                    g.SetDefaultQuality();
+                }
+
+
+                if (series.Symbol != UILinePointSymbol.None)
+                {
+                    using (Brush br = new SolidBrush(ChartStyle.BackColor))
+                    using (Pen pn = new Pen(series.SymbolColor, series.SymbolLineWidth))
+                    {
+                        foreach (var p in series.Points)
+                        {
+                            switch (series.Symbol)
+                            {
+                                case UILinePointSymbol.Square:
+                                    g.FillRectangle(br, p.X - series.SymbolSize, p.Y - series.SymbolSize, series.SymbolSize * 2, series.SymbolSize * 2);
+                                    g.DrawRectangle(pn, p.X - series.SymbolSize, p.Y - series.SymbolSize, series.SymbolSize * 2, series.SymbolSize * 2);
+                                    break;
+                                case UILinePointSymbol.Diamond:
+                                    {
+                                        PointF pt1 = new PointF(p.X - series.SymbolSize, p.Y);
+                                        PointF pt2 = new PointF(p.X, p.Y - series.SymbolSize);
+                                        PointF pt3 = new PointF(p.X + series.SymbolSize, p.Y);
+                                        PointF pt4 = new PointF(p.X, p.Y + series.SymbolSize);
+                                        PointF[] pts = { pt1, pt2, pt3, pt4, pt1 };
+                                        g.SetHighQuality();
+                                        GraphicsPath path = pts.Path();
+                                        g.FillPath(br, path);
+                                        g.DrawPath(pn, path);
+                                        path.Dispose();
+                                    }
+                                    break;
+                                case UILinePointSymbol.Triangle:
+                                    {
+                                        PointF pt1 = new PointF(p.X, p.Y - series.SymbolSize);
+                                        PointF pt2 = new PointF(p.X - series.SymbolSize * 0.866f, p.Y + series.SymbolSize * 0.5f);
+                                        PointF pt3 = new PointF(p.X + series.SymbolSize * 0.866f, p.Y + series.SymbolSize * 0.5f);
+                                        PointF[] pts = { pt1, pt2, pt3, pt1 };
+                                        g.SetHighQuality();
+                                        GraphicsPath path = pts.Path();
+                                        g.FillPath(br, path);
+                                        g.DrawPath(pn, path);
+                                        path.Dispose();
+                                    }
+                                    break;
+                                case UILinePointSymbol.Circle:
+                                    g.SetHighQuality();
+                                    g.FillEllipse(br, p.X - series.SymbolSize, p.Y - series.SymbolSize, series.SymbolSize * 2, series.SymbolSize * 2);
+                                    g.DrawEllipse(pn, p.X - series.SymbolSize, p.Y - series.SymbolSize, series.SymbolSize * 2, series.SymbolSize * 2);
+                                    break;
+                                case UILinePointSymbol.Plus:
+                                    g.DrawLine(pn, p.X - series.SymbolSize, p.Y, p.X + series.SymbolSize, p.Y);
+                                    g.DrawLine(pn, p.X, p.Y - series.SymbolSize, p.X, p.Y + series.SymbolSize);
+                                    break;
+                                case UILinePointSymbol.Star:
+                                    g.SetHighQuality();
+                                    g.DrawLine(pn, p.X, p.Y - series.SymbolSize, p.X, p.Y + series.SymbolSize);
+                                    g.DrawLine(pn, p.X - series.SymbolSize * 0.866f, p.Y + series.SymbolSize * 0.5f,
+                                        p.X + series.SymbolSize * 0.866f, p.Y - series.SymbolSize * 0.5f);
+                                    g.DrawLine(pn, p.X - series.SymbolSize * 0.866f, p.Y - series.SymbolSize * 0.5f,
+                                        p.X + series.SymbolSize * 0.866f, p.Y + series.SymbolSize * 0.5f);
+                                    break;
+                            }
+                        }
+                    }
+
+                    g.SetDefaultQuality();
+                }
 
                 idx++;
             }
@@ -309,5 +410,67 @@ namespace Sunny.UI
                     g.DrawString(line.Name, SubFont, line.Color, Width - sf.Width - 4 - LineOption.Grid.Right, pos - 2 - sf.Height);
             }
         }
+
+        private readonly List<UILineSelectPoint> selectPoints = new List<UILineSelectPoint>();
+        private readonly List<UILineSelectPoint> selectPointsTemp = new List<UILineSelectPoint>();
+
+        protected override void OnMouseMove(MouseEventArgs e)
+        {
+            base.OnMouseMove(e);
+            if (!NeedDraw) return;
+
+            selectPointsTemp.Clear();
+            foreach (var series in LineOption.Series.Values)
+            {
+                if (series.GetNearestPoint(e.Location, 4, out double x, out double y, out int index))
+                {
+                    UILineSelectPoint point = new UILineSelectPoint();
+                    point.Name = series.Name;
+                    point.Index = index;
+                    point.X = x;
+                    point.Y = y;
+                    selectPointsTemp.Add(point);
+                }
+            }
+
+            bool isNew = false;
+            if (selectPointsTemp.Count != selectPoints.Count)
+            {
+                isNew = true;
+            }
+            else
+            {
+                Dictionary<string, UILineSelectPoint> points = selectPoints.ToDictionary(p => p.Name);
+                foreach (var point in selectPointsTemp)
+                {
+                    if (!points.ContainsKey(point.Name))
+                    {
+                        isNew = true;
+                        break;
+                    }
+
+                    if (points[point.Name].Index != point.Index)
+                    {
+                        isNew = true;
+                        break;
+                    }
+                }
+            }
+
+            if (isNew)
+            {
+                selectPoints.Clear();
+                foreach (var point in selectPointsTemp)
+                {
+                    selectPoints.Add(point);
+                }
+
+                PointValue?.Invoke(this, selectPoints);
+            }
+        }
+
+        public delegate void OnPointValue(object sender, List<UILineSelectPoint> points);
+
+        public event OnPointValue PointValue;
     }
 }
diff --git a/SunnyUI/Charts/UILineChartOption.cs b/SunnyUI/Charts/UILineChartOption.cs
index acfe7586..4b80d5c5 100644
--- a/SunnyUI/Charts/UILineChartOption.cs
+++ b/SunnyUI/Charts/UILineChartOption.cs
@@ -3,7 +3,7 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Drawing;
 
-namespace Sunny.UI.Charts
+namespace Sunny.UI
 {
     public sealed class UILineOption : UIOption, IDisposable
     {
@@ -29,10 +29,20 @@ namespace Sunny.UI.Charts
         public readonly List<UIScaleLine> XAxisScaleLines = new List<UIScaleLine>();
 
         public readonly List<UIScaleLine> YAxisScaleLines = new List<UIScaleLine>();
-        public void AddSeries(UILineSeries series)
+
+        public UILineSeries AddSeries(UILineSeries series)
         {
-            if (series.Name.IsNullOrEmpty()) return;
+            if (series.Name.IsNullOrEmpty()) return null;
             Series.TryAdd(series.Name, series);
+            return series;
+        }
+
+        public UILineSeries AddSeries(string name)
+        {
+            if (name.IsNullOrEmpty()) return null;
+            UILineSeries series = new UILineSeries(name);
+            Series.TryAdd(series.Name, series);
+            return series;
         }
 
         public void AddData(string name, double x, double y)
@@ -150,11 +160,13 @@ namespace Sunny.UI.Charts
     {
         public string Name { get; private set; }
 
-        public float Width { get; set; } = 1;
+        public float Width { get; set; } = 2;
         public Color Color { get; set; }
 
         public UILinePointSymbol Symbol { get; set; } = UILinePointSymbol.None;
-        public int SymbolSize { get; set; } = 1;
+        public int SymbolSize { get; set; } = 4;
+
+        public int SymbolLineWidth { get; set; } = 1;
 
         public Color SymbolColor { get; set; }
 
@@ -181,13 +193,47 @@ namespace Sunny.UI.Charts
 
         public readonly List<PointF> Points = new List<PointF>();
 
+        private readonly List<double> PointsX = new List<double>();
+
+        private readonly List<double> PointsY = new List<double>();
+
         public int DataCount => XData.Count;
 
+        public bool GetNearestPoint(Point p, int offset, out double x, out double y, out int index)
+        {
+            index = PointsX.BinarySearchNearIndex(p.X);
+            if (p.X >= PointsX[index] - offset && p.X <= PointsX[index] + offset &&
+                p.Y >= PointsY[index] - offset && p.Y <= PointsY[index] + offset)
+            {
+                x = XData[index];
+                y = YData[index];
+                return true;
+            }
+
+            x = 0;
+            y = 0;
+            return false;
+        }
+
         public void Clear()
         {
             XData.Clear();
             YData.Clear();
+            ClearPoints();
+        }
+
+        public void ClearPoints()
+        {
             Points.Clear();
+            PointsX.Clear();
+            PointsY.Clear();
+        }
+
+        public void AddPoint(PointF point)
+        {
+            Points.Add(point);
+            PointsX.Add(point.X);
+            PointsY.Add(point.Y);
         }
 
         public void Add(double x, double y)
@@ -221,4 +267,15 @@ namespace Sunny.UI.Charts
         Plus,
         Star
     }
+
+    public struct UILineSelectPoint
+    {
+        public string Name { get; set; }
+
+        public int Index { get; set; }
+
+        public double X { get; set; }
+
+        public double Y { get; set; }
+    }
 }
diff --git a/SunnyUI/Charts/UIOption.cs b/SunnyUI/Charts/UIOption.cs
index fe0611c1..e7cb2998 100644
--- a/SunnyUI/Charts/UIOption.cs
+++ b/SunnyUI/Charts/UIOption.cs
@@ -238,6 +238,67 @@ namespace Sunny.UI
             degree_end = end2;
         }
 
+        /// <summary>
+        /// 计算刻度
+        /// 起始值必须小于结束值
+        /// </summary>
+        /// <param name="start">起始值</param>
+        /// <param name="end">结束值</param>
+        /// <param name="expect_num">期望刻度数量，实际数接近此数</param>
+        /// <param name="degree_start">刻度起始值，须乘以间隔使用</param>
+        /// <param name="degree_end">刻度结束值，须乘以间隔使用</param>
+        /// <param name="degree_gap">刻度间隔</param>
+        public static void CalcDateTimeDegreeScale(double start, double end, int expect_num,
+            out int degree_start, out int degree_end, out double degree_gap)
+        {
+            if (start >= end)
+            {
+                throw new Exception("起始值必须小于结束值");
+            }
+
+            double differ = end - start;
+            double differ_gap = differ / (expect_num - 1); //35, 4.6, 0.27
+
+            double exponent = Math.Log10(differ_gap) - 1; //0.54, -0.34, -1.57
+            int _exponent = (int)exponent; //0, 0=>-1, -1=>-2
+            if (exponent < 0 && Math.Abs(exponent) > 1e-8)
+            {
+                _exponent--;
+            }
+
+            int step = (int)(differ_gap / Math.Pow(10, _exponent)); //35, 46, 27
+            int[] fix_steps = new int[] { 10, 20, 30, 60, 120 };
+            int fix_step = 10; //25, 50, 25
+            for (int i = fix_steps.Length - 1; i >= 1; i--)
+            {
+                if (step > (fix_steps[i] + fix_steps[i - 1]) / 2)
+                {
+                    fix_step = fix_steps[i];
+                    break;
+                }
+            }
+
+            degree_gap = fix_step * Math.Pow(10, _exponent); //25, 5, 0.25
+
+            double start1 = start / degree_gap;
+            int start2 = (int)start1;
+            if (start1 < 0 && Math.Abs(start1 - start2) > 1e-8)
+            {
+                start2--;
+            }
+
+            degree_start = start2;
+
+            double end1 = end / degree_gap;
+            int end2 = (int)end1;
+            if (end1 >= 0 && Math.Abs(end1 - end2) > 1e-8)
+            {
+                end2++;
+            }
+
+            degree_end = end2;
+        }
+
         /// <summary>
         /// 计算刻度
         /// 起始值必须小于结束值