点线距测量工具实现

XP.ImageProcessing.RoiControl/Controls/MeasureEventArgs.cs

@@ -9,6 +9,7 @@ namespace XP.ImageProcessing.RoiControl.Controls
         public Point P2 { get; }
         public double Distance { get; }
         public int TotalCount { get; }
+        public string MeasureType { get; set; }
 
         public MeasureCompletedEventArgs(RoutedEvent routedEvent, Point p1, Point p2, double distance, int totalCount)
             : base(routedEvent)

XP.ImageProcessing.RoiControl/Controls/PolygonRoiCanvas.xaml.cs

@@ -243,6 +243,42 @@ namespace XP.ImageProcessing.RoiControl.Controls
 
         #endregion Dependency Properties
 
+        #region Measurement Config
+
+        public static readonly DependencyProperty PixelSizeProperty =
+            DependencyProperty.Register(nameof(PixelSize), typeof(double), typeof(PolygonRoiCanvas),
+                new PropertyMetadata(1.0));
+
+        /// <summary>每像素对应的物理尺寸（= 探测器像素尺寸 / 放大倍率），默认 1.0</summary>
+        public double PixelSize
+        {
+            get => (double)GetValue(PixelSizeProperty);
+            set => SetValue(PixelSizeProperty, value);
+        }
+
+        public static readonly DependencyProperty MeasureUnitProperty =
+            DependencyProperty.Register(nameof(MeasureUnit), typeof(string), typeof(PolygonRoiCanvas),
+                new PropertyMetadata("px"));
+
+        /// <summary>测量单位，默认 "px"，可设为 "mm"/"μm"/"cm"</summary>
+        public string MeasureUnit
+        {
+            get => (string)GetValue(MeasureUnitProperty);
+            set => SetValue(MeasureUnitProperty, value);
+        }
+
+        /// <summary>将像素距离转换为物理距离文本</summary>
+        internal string FormatDistance(double pixelDistance)
+        {
+            string unit = MeasureUnit ?? "px";
+            if (unit == "px" || PixelSize <= 0 || PixelSize == 1.0)
+                return $"{pixelDistance:F2} px";
+            double physical = pixelDistance * PixelSize;
+            return $"{physical:F4} {unit}";
+        }
+
+        #endregion Measurement Config
+
         #region Crosshair
 
         public static readonly DependencyProperty ShowCrosshairProperty =
@@ -288,43 +324,65 @@ namespace XP.ImageProcessing.RoiControl.Controls
 
         #region Measurement
 
-        public static readonly DependencyProperty IsMeasuringProperty =
-            DependencyProperty.Register(nameof(IsMeasuring), typeof(bool), typeof(PolygonRoiCanvas),
-                new PropertyMetadata(false, OnIsMeasuringChanged));
+        public static readonly DependencyProperty CurrentMeasureModeProperty =
+            DependencyProperty.Register(nameof(CurrentMeasureMode), typeof(Models.MeasureMode), typeof(PolygonRoiCanvas),
+                new PropertyMetadata(Models.MeasureMode.None, OnMeasureModeChanged));
 
-        public bool IsMeasuring
+        public Models.MeasureMode CurrentMeasureMode
         {
-            get => (bool)GetValue(IsMeasuringProperty);
-            set => SetValue(IsMeasuringProperty, value);
+            get => (Models.MeasureMode)GetValue(CurrentMeasureModeProperty);
+            set => SetValue(CurrentMeasureModeProperty, value);
         }
 
+        // 保留 IsMeasuring 作为便捷属性
+        public bool IsMeasuring => CurrentMeasureMode != Models.MeasureMode.None;
+
         private Canvas _measureOverlay;
-        private readonly System.Collections.Generic.List<Models.MeasureGroup> _measureGroups = new();
+        private readonly System.Collections.Generic.List<Models.MeasureGroup> _ppGroups = new();
+        private readonly System.Collections.Generic.List<Models.PointToLineGroup> _ptlGroups = new();
+
+        // 点点距临时状态
         private Ellipse _pendingDot;
         private Point? _pendingPoint;
-        private Ellipse _mDraggingDot;
-        private Models.MeasureGroup _mDraggingGroup;
-        private bool _mDraggingIsDot1;
 
-        private static void OnIsMeasuringChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        // 点线距临时状态
+        private int _ptlClickCount;
+        private Ellipse _ptlTempDot1, _ptlTempDot2;
+        private Line _ptlTempLine;
+        private Point? _ptlTempL1, _ptlTempL2;
+
+        // 拖拽状态
+        private Ellipse _mDraggingDot;
+        private object _mDraggingOwner; // MeasureGroup 或 PointToLineGroup
+        private string _mDraggingRole;  // "Dot1","Dot2","DotL1","DotL2","DotP"
+
+        private static void OnMeasureModeChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
         {
             var c = (PolygonRoiCanvas)d;
-            if ((bool)e.NewValue)
+            var newMode = (Models.MeasureMode)e.NewValue;
+            if (newMode != Models.MeasureMode.None)
             {
                 c.EnsureMeasureOverlay();
             }
             else
             {
-                // 退出测量模式：只清除未完成的临时点，保留已完成的测量线
-                if (c._pendingDot != null && c._measureOverlay != null)
-                {
-                    c._measureOverlay.Children.Remove(c._pendingDot);
-                    c._pendingDot = null;
-                }
-                c._pendingPoint = null;
+                // 退出测量模式：清除未完成的临时元素
+                c.ClearPendingElements();
             }
         }
 
+        private void ClearPendingElements()
+        {
+            if (_measureOverlay == null) return;
+            if (_pendingDot != null) { _measureOverlay.Children.Remove(_pendingDot); _pendingDot = null; }
+            _pendingPoint = null;
+            if (_ptlTempDot1 != null) { _measureOverlay.Children.Remove(_ptlTempDot1); _ptlTempDot1 = null; }
+            if (_ptlTempDot2 != null) { _measureOverlay.Children.Remove(_ptlTempDot2); _ptlTempDot2 = null; }
+            if (_ptlTempLine != null) { _measureOverlay.Children.Remove(_ptlTempLine); _ptlTempLine = null; }
+            _ptlTempL1 = _ptlTempL2 = null;
+            _ptlClickCount = 0;
+        }
+
         private void EnsureMeasureOverlay()
         {
             if (_measureOverlay != null) return;
@@ -336,77 +394,134 @@ namespace XP.ImageProcessing.RoiControl.Controls
 
         private void RemoveMeasureOverlay()
         {
-            if (_measureOverlay != null)
-            {
-                mainCanvas.Children.Remove(_measureOverlay);
-                _measureOverlay = null;
-            }
-            _measureGroups.Clear();
-            _pendingDot = null;
-            _pendingPoint = null;
-            _mDraggingDot = null;
-            _mDraggingGroup = null;
+            if (_measureOverlay != null) { mainCanvas.Children.Remove(_measureOverlay); _measureOverlay = null; }
+            _ppGroups.Clear();
+            _ptlGroups.Clear();
+            _pendingDot = null; _pendingPoint = null;
+            _ptlTempDot1 = _ptlTempDot2 = null; _ptlTempLine = null;
+            _ptlTempL1 = _ptlTempL2 = null; _ptlClickCount = 0;
+            _mDraggingDot = null; _mDraggingOwner = null;
         }
 
-        /// <summary>清除所有测量绘制</summary>
-        public void ClearMeasurements()
-        {
-            RemoveMeasureOverlay();
-        }
+        public void ClearMeasurements() => RemoveMeasureOverlay();
+        public int MeasureCount => _ppGroups.Count + _ptlGroups.Count;
 
-        /// <summary>获取当前测量组数量</summary>
-        public int MeasureCount => _measureGroups.Count;
+        // ── 点击分发 ──
 
-        /// <summary>处理测量模式下的画布点击</summary>
         private void HandleMeasureClick(Point pos)
         {
             if (_measureOverlay == null) EnsureMeasureOverlay();
             if (_measureOverlay == null) return;
 
+            if (CurrentMeasureMode == Models.MeasureMode.PointDistance)
+                HandlePointDistanceClick(pos);
+            else if (CurrentMeasureMode == Models.MeasureMode.PointToLine)
+                HandlePointToLineClick(pos);
+        }
+
+        // ── 点点距 ──
+
+        private void HandlePointDistanceClick(Point pos)
+        {
             if (!_pendingPoint.HasValue)
             {
                 _pendingPoint = pos;
-                _pendingDot = CreateMeasureDot(Brushes.Red);
+                _pendingDot = CreateMDot(Brushes.Red);
                 _measureOverlay.Children.Add(_pendingDot);
-                SetMeasureDotPos(_pendingDot, pos);
-                RaiseMeasureStatusChanged($"点点距测量 - 第一点: ({pos.X:F0}, {pos.Y:F0})，请点击第二个点");
+                SetDotPos(_pendingDot, pos);
+                RaiseMeasureStatusChanged($"点点距 - 第一点: ({pos.X:F0}, {pos.Y:F0})，请点击第二个点");
             }
             else
             {
-                var g = CreateMeasureGroup(_pendingPoint.Value, pos);
-                _measureGroups.Add(g);
+                var g = CreatePPGroup(_pendingPoint.Value, pos);
+                _ppGroups.Add(g);
                 _measureOverlay.Children.Remove(_pendingDot);
-                _pendingDot = null;
-                _pendingPoint = null;
-                RaiseMeasureCompleted(g);
-
-                // 完成一条测量后自动退出测量模式
-                IsMeasuring = false;
+                _pendingDot = null; _pendingPoint = null;
+                RaiseMeasureCompleted(g.P1, g.P2, g.Distance, MeasureCount, "PointDistance");
+                CurrentMeasureMode = Models.MeasureMode.None;
             }
         }
 
-        private Models.MeasureGroup CreateMeasureGroup(Point p1, Point p2)
+        private Models.MeasureGroup CreatePPGroup(Point p1, Point p2)
         {
             var g = new Models.MeasureGroup { P1 = p1, P2 = p2 };
             g.Line = new Line { Stroke = Brushes.Lime, StrokeThickness = 2, IsHitTestVisible = false };
-            _measureOverlay.Children.Add(g.Line);
-
             g.Label = new TextBlock { Foreground = Brushes.Yellow, FontSize = 13, FontWeight = FontWeights.Bold, IsHitTestVisible = false };
-            _measureOverlay.Children.Add(g.Label);
-
-            g.Dot1 = CreateMeasureDot(Brushes.Red);
-            g.Dot2 = CreateMeasureDot(Brushes.Blue);
-            _measureOverlay.Children.Add(g.Dot1);
-            _measureOverlay.Children.Add(g.Dot2);
-
-            SetMeasureDotPos(g.Dot1, p1);
-            SetMeasureDotPos(g.Dot2, p2);
-            g.UpdateLine();
-            g.UpdateLabel();
+            g.Dot1 = CreateMDot(Brushes.Red);
+            g.Dot2 = CreateMDot(Brushes.Blue);
+            foreach (UIElement el in new UIElement[] { g.Line, g.Label, g.Dot1, g.Dot2 })
+                _measureOverlay.Children.Add(el);
+            SetDotPos(g.Dot1, p1); SetDotPos(g.Dot2, p2);
+            g.UpdateLine(); g.UpdateLabel(FormatDistance(g.Distance));
             return g;
         }
 
-        private Ellipse CreateMeasureDot(Brush fill)
+        // ── 点线距 ──
+
+        private void HandlePointToLineClick(Point pos)
+        {
+            _ptlClickCount++;
+
+            if (_ptlClickCount == 1)
+            {
+                _ptlTempL1 = pos;
+                _ptlTempDot1 = CreateMDot(Brushes.Lime);
+                _measureOverlay.Children.Add(_ptlTempDot1);
+                SetDotPos(_ptlTempDot1, pos);
+                RaiseMeasureStatusChanged($"点线距 - 直线端点1: ({pos.X:F0}, {pos.Y:F0})，请点击直线端点2");
+            }
+            else if (_ptlClickCount == 2)
+            {
+                _ptlTempL2 = pos;
+                _ptlTempDot2 = CreateMDot(Brushes.Lime);
+                _measureOverlay.Children.Add(_ptlTempDot2);
+                SetDotPos(_ptlTempDot2, pos);
+                _ptlTempLine = new Line { Stroke = Brushes.Lime, StrokeThickness = 2, IsHitTestVisible = false,
+                    X1 = _ptlTempL1.Value.X, Y1 = _ptlTempL1.Value.Y, X2 = pos.X, Y2 = pos.Y };
+                _measureOverlay.Children.Add(_ptlTempLine);
+                RaiseMeasureStatusChanged($"点线距 - 直线已定义，请点击测量点");
+            }
+            else if (_ptlClickCount == 3)
+            {
+                // 完成：创建正式组，移除临时元素
+                var g = CreatePTLGroup(_ptlTempL1.Value, _ptlTempL2.Value, pos);
+                _ptlGroups.Add(g);
+
+                if (_ptlTempDot1 != null) _measureOverlay.Children.Remove(_ptlTempDot1);
+                if (_ptlTempDot2 != null) _measureOverlay.Children.Remove(_ptlTempDot2);
+                if (_ptlTempLine != null) _measureOverlay.Children.Remove(_ptlTempLine);
+                _ptlTempDot1 = _ptlTempDot2 = null; _ptlTempLine = null;
+                _ptlTempL1 = _ptlTempL2 = null; _ptlClickCount = 0;
+
+                var foot = g.FootPoint;
+                RaiseMeasureCompleted(g.P, foot, g.Distance, MeasureCount, "PointToLine");
+                CurrentMeasureMode = Models.MeasureMode.None;
+            }
+        }
+
+        private Models.PointToLineGroup CreatePTLGroup(Point l1, Point l2, Point p)
+        {
+            var g = new Models.PointToLineGroup { L1 = l1, L2 = l2, P = p };
+            g.MainLine = new Line { Stroke = Brushes.Lime, StrokeThickness = 2, IsHitTestVisible = false };
+            g.ExtLine = new Line { Stroke = Brushes.Lime, StrokeThickness = 1, IsHitTestVisible = false,
+                StrokeDashArray = new DoubleCollection { 4, 2 }, Visibility = Visibility.Collapsed };
+            g.PerpLine = new Line { Stroke = Brushes.Yellow, StrokeThickness = 1, IsHitTestVisible = false,
+                StrokeDashArray = new DoubleCollection { 4, 2 } };
+            g.FootDot = new Ellipse { Width = 8, Height = 8, Fill = Brushes.Cyan, Stroke = Brushes.White, StrokeThickness = 1, IsHitTestVisible = false };
+            g.Label = new TextBlock { Foreground = Brushes.Yellow, FontSize = 13, FontWeight = FontWeights.Bold, IsHitTestVisible = false };
+            g.DotL1 = CreateMDot(Brushes.Lime);
+            g.DotL2 = CreateMDot(Brushes.Lime);
+            g.DotP = CreateMDot(Brushes.Red);
+            foreach (UIElement el in new UIElement[] { g.MainLine, g.ExtLine, g.PerpLine, g.FootDot, g.Label, g.DotL1, g.DotL2, g.DotP })
+                _measureOverlay.Children.Add(el);
+            SetDotPos(g.DotL1, l1); SetDotPos(g.DotL2, l2); SetDotPos(g.DotP, p);
+            g.UpdateVisuals(FormatDistance(g.Distance));
+            return g;
+        }
+
+        // ── 共用：圆点创建、定位、拖拽、删除 ──
+
+        private Ellipse CreateMDot(Brush fill)
         {
             var dot = new Ellipse { Width = 12, Height = 12, Fill = fill, Stroke = Brushes.White, StrokeThickness = 1.5, Cursor = Cursors.Hand };
             dot.SetValue(ContextMenuService.IsEnabledProperty, false);
@@ -417,7 +532,7 @@ namespace XP.ImageProcessing.RoiControl.Controls
             return dot;
         }
 
-        private static void SetMeasureDotPos(Ellipse dot, Point pos)
+        private static void SetDotPos(Ellipse dot, Point pos)
         {
             Canvas.SetLeft(dot, pos.X - dot.Width / 2);
             Canvas.SetTop(dot, pos.Y - dot.Height / 2);
@@ -426,51 +541,87 @@ namespace XP.ImageProcessing.RoiControl.Controls
         private void MDot_Down(object sender, MouseButtonEventArgs e)
         {
             if (sender is not Ellipse dot) return;
-            foreach (var g in _measureGroups)
+            // 查找点点距组
+            foreach (var g in _ppGroups)
             {
-                if (g.Dot1 == dot) { _mDraggingGroup = g; _mDraggingIsDot1 = true; break; }
-                if (g.Dot2 == dot) { _mDraggingGroup = g; _mDraggingIsDot1 = false; break; }
+                if (g.Dot1 == dot) { _mDraggingOwner = g; _mDraggingRole = "Dot1"; break; }
+                if (g.Dot2 == dot) { _mDraggingOwner = g; _mDraggingRole = "Dot2"; break; }
             }
-            if (_mDraggingGroup != null) { _mDraggingDot = dot; dot.CaptureMouse(); e.Handled = true; }
+            // 查找点线距组
+            if (_mDraggingOwner == null)
+            {
+                foreach (var g in _ptlGroups)
+                {
+                    if (g.DotL1 == dot) { _mDraggingOwner = g; _mDraggingRole = "DotL1"; break; }
+                    if (g.DotL2 == dot) { _mDraggingOwner = g; _mDraggingRole = "DotL2"; break; }
+                    if (g.DotP == dot) { _mDraggingOwner = g; _mDraggingRole = "DotP"; break; }
+                }
+            }
+            if (_mDraggingOwner != null) { _mDraggingDot = dot; dot.CaptureMouse(); e.Handled = true; }
         }
 
         private void MDot_Move(object sender, MouseEventArgs e)
         {
-            if (_mDraggingDot == null || _mDraggingGroup == null || _measureOverlay == null) return;
+            if (_mDraggingDot == null || _mDraggingOwner == null || _measureOverlay == null) return;
             if (e.LeftButton != MouseButtonState.Pressed) return;
             var pos = e.GetPosition(_measureOverlay);
-            SetMeasureDotPos(_mDraggingDot, pos);
-            if (_mDraggingIsDot1) _mDraggingGroup.P1 = pos; else _mDraggingGroup.P2 = pos;
-            _mDraggingGroup.UpdateLine();
-            _mDraggingGroup.UpdateLabel();
-            RaiseMeasureCompleted(_mDraggingGroup);
+            SetDotPos(_mDraggingDot, pos);
+
+            if (_mDraggingOwner is Models.MeasureGroup ppg)
+            {
+                if (_mDraggingRole == "Dot1") ppg.P1 = pos; else ppg.P2 = pos;
+                ppg.UpdateLine(); ppg.UpdateLabel(FormatDistance(ppg.Distance));
+                RaiseMeasureCompleted(ppg.P1, ppg.P2, ppg.Distance, MeasureCount, "PointDistance");
+            }
+            else if (_mDraggingOwner is Models.PointToLineGroup ptlg)
+            {
+                if (_mDraggingRole == "DotL1") ptlg.L1 = pos;
+                else if (_mDraggingRole == "DotL2") ptlg.L2 = pos;
+                else if (_mDraggingRole == "DotP") ptlg.P = pos;
+                ptlg.UpdateVisuals(FormatDistance(ptlg.Distance));
+                var foot = ptlg.FootPoint;
+                RaiseMeasureCompleted(ptlg.P, foot, ptlg.Distance, MeasureCount, "PointToLine");
+            }
             e.Handled = true;
         }
 
         private void MDot_Up(object sender, MouseButtonEventArgs e)
         {
-            if (_mDraggingDot != null) { _mDraggingDot.ReleaseMouseCapture(); _mDraggingDot = null; _mDraggingGroup = null; e.Handled = true; }
+            if (_mDraggingDot != null) { _mDraggingDot.ReleaseMouseCapture(); _mDraggingDot = null; _mDraggingOwner = null; e.Handled = true; }
         }
 
         private void MDot_RightClick(object sender, MouseButtonEventArgs e)
         {
             if (sender is not Ellipse dot || _measureOverlay == null) return;
-            Models.MeasureGroup target = null;
-            foreach (var g in _measureGroups)
+
+            // 点点距删除
+            foreach (var g in _ppGroups)
             {
-                if (g.Dot1 == dot || g.Dot2 == dot) { target = g; break; }
+                if (g.Dot1 == dot || g.Dot2 == dot)
+                {
+                    foreach (var el in new UIElement[] { g.Dot1, g.Dot2, g.Line, g.Label })
+                        _measureOverlay.Children.Remove(el);
+                    _ppGroups.Remove(g);
+                    RaiseMeasureStatusChanged($"已删除测量 | 剩余 {MeasureCount} 条");
+                    e.Handled = true; return;
+                }
+            }
+            // 点线距删除
+            foreach (var g in _ptlGroups)
+            {
+                if (g.DotL1 == dot || g.DotL2 == dot || g.DotP == dot)
+                {
+                    foreach (var el in new UIElement[] { g.DotL1, g.DotL2, g.DotP, g.MainLine, g.ExtLine, g.PerpLine, g.FootDot, g.Label })
+                        _measureOverlay.Children.Remove(el);
+                    _ptlGroups.Remove(g);
+                    RaiseMeasureStatusChanged($"已删除测量 | 剩余 {MeasureCount} 条");
+                    e.Handled = true; return;
+                }
             }
-            if (target == null) return;
-            _measureOverlay.Children.Remove(target.Dot1);
-            _measureOverlay.Children.Remove(target.Dot2);
-            _measureOverlay.Children.Remove(target.Line);
-            _measureOverlay.Children.Remove(target.Label);
-            _measureGroups.Remove(target);
-            RaiseMeasureStatusChanged($"已删除测量线 | 剩余 {_measureGroups.Count} 条");
-            e.Handled = true;
         }
 
-        // 测量事件
+        // ── 事件 ──
+
         public static readonly RoutedEvent MeasureCompletedEvent =
             EventManager.RegisterRoutedEvent(nameof(MeasureCompleted), RoutingStrategy.Bubble,
                 typeof(RoutedEventHandler), typeof(PolygonRoiCanvas));
@@ -481,9 +632,9 @@ namespace XP.ImageProcessing.RoiControl.Controls
             remove { RemoveHandler(MeasureCompletedEvent, value); }
         }
 
-        private void RaiseMeasureCompleted(Models.MeasureGroup g)
+        private void RaiseMeasureCompleted(Point p1, Point p2, double distance, int totalCount, string measureType)
         {
-            RaiseEvent(new MeasureCompletedEventArgs(MeasureCompletedEvent, g.P1, g.P2, g.Distance, _measureGroups.Count));
+            RaiseEvent(new MeasureCompletedEventArgs(MeasureCompletedEvent, p1, p2, distance, totalCount) { MeasureType = measureType });
         }
 
         public static readonly RoutedEvent MeasureStatusChangedEvent =

XP.ImageProcessing.RoiControl/Models/MeasureGroup.cs

@@ -32,9 +32,9 @@ namespace XP.ImageProcessing.RoiControl.Models
             Line.Visibility = Visibility.Visible;
         }
 
-        public void UpdateLabel(string unit = "px")
+        public void UpdateLabel(string distanceText = null)
         {
-            Label.Text = $"{Distance:F2} {unit}";
+            Label.Text = distanceText ?? $"{Distance:F2} px";
             Canvas.SetLeft(Label, (P1.X + P2.X) / 2 + 8);
             Canvas.SetTop(Label, (P1.Y + P2.Y) / 2 - 18);
             Label.Visibility = Visibility.Visible;

XP.ImageProcessing.RoiControl/Models/MeasureMode.cs

@@ -0,0 +1,9 @@
+namespace XP.ImageProcessing.RoiControl.Models
+{
+    public enum MeasureMode
+    {
+        None,
+        PointDistance,
+        PointToLine
+    }
+}

XP.ImageProcessing.RoiControl/Models/PointToLineGroup.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Shapes;
+
+namespace XP.ImageProcessing.RoiControl.Models
+{
+    /// <summary>一次点线距测量的所有视觉元素（直线两端点 + 测量点 + 垂线 + 标签）</summary>
+    public class PointToLineGroup
+    {
+        public Ellipse DotL1 { get; set; }  // 直线端点1
+        public Ellipse DotL2 { get; set; }  // 直线端点2
+        public Ellipse DotP { get; set; }   // 测量点
+        public Line MainLine { get; set; }  // 原始线段（实线）
+        public Line ExtLine { get; set; }   // 延长线（虚线）
+        public Line PerpLine { get; set; }  // 垂线（测量点→垂足）
+        public Ellipse FootDot { get; set; } // 垂足
+        public TextBlock Label { get; set; }
+        public Point L1 { get; set; }
+        public Point L2 { get; set; }
+        public Point P { get; set; }
+
+        public double Distance
+        {
+            get
+            {
+                double abx = L2.X - L1.X, aby = L2.Y - L1.Y;
+                double abLen = Math.Sqrt(abx * abx + aby * aby);
+                if (abLen < 0.001) return 0;
+                return Math.Abs(abx * (L1.Y - P.Y) - aby * (L1.X - P.X)) / abLen;
+            }
+        }
+
+        public Point FootPoint
+        {
+            get
+            {
+                double abx = L2.X - L1.X, aby = L2.Y - L1.Y;
+                double abLen2 = abx * abx + aby * aby;
+                if (abLen2 < 0.001) return L1;
+                double t = ((P.X - L1.X) * abx + (P.Y - L1.Y) * aby) / abLen2;
+                return new Point(L1.X + t * abx, L1.Y + t * aby);
+            }
+        }
+
+        public void UpdateVisuals(string distanceText)
+        {
+            double abx = L2.X - L1.X, aby = L2.Y - L1.Y;
+            double abLen2 = abx * abx + aby * aby;
+            double t = abLen2 < 0.001 ? 0 : ((P.X - L1.X) * abx + (P.Y - L1.Y) * aby) / abLen2;
+            var foot = FootPoint;
+
+            // 主直线：始终画原始线段
+            MainLine.X1 = L1.X; MainLine.Y1 = L1.Y;
+            MainLine.X2 = L2.X; MainLine.Y2 = L2.Y;
+            MainLine.Visibility = Visibility.Visible;
+
+            // 延长线：垂足在线段外时画虚线延伸
+            if (t < 0)
+            {
+                ExtLine.X1 = foot.X; ExtLine.Y1 = foot.Y;
+                ExtLine.X2 = L1.X; ExtLine.Y2 = L1.Y;
+                ExtLine.Visibility = Visibility.Visible;
+            }
+            else if (t > 1)
+            {
+                ExtLine.X1 = L2.X; ExtLine.Y1 = L2.Y;
+                ExtLine.X2 = foot.X; ExtLine.Y2 = foot.Y;
+                ExtLine.Visibility = Visibility.Visible;
+            }
+            else
+            {
+                ExtLine.Visibility = Visibility.Collapsed;
+            }
+
+            // 垂线
+            PerpLine.X1 = P.X; PerpLine.Y1 = P.Y;
+            PerpLine.X2 = foot.X; PerpLine.Y2 = foot.Y;
+            PerpLine.Visibility = Visibility.Visible;
+
+            // 垂足
+            Canvas.SetLeft(FootDot, foot.X - FootDot.Width / 2);
+            Canvas.SetTop(FootDot, foot.Y - FootDot.Height / 2);
+            FootDot.Visibility = Visibility.Visible;
+
+            // 标签
+            Label.Text = distanceText ?? $"{Distance:F2} px";
+            Canvas.SetLeft(Label, (P.X + foot.X) / 2 + 8);
+            Canvas.SetTop(Label, (P.Y + foot.Y) / 2 - 18);
+            Label.Visibility = Visibility.Visible;
+        }
+
+        public void UpdateVisuals() => UpdateVisuals(null);
+    }
+}

XplorePlane/ViewModels/Main/MainViewModel.cs

@@ -449,7 +449,7 @@ namespace XplorePlane.ViewModels
         private void ExecutePointLineDistanceMeasure()
         {
             _logger.Info("点线距测量功能已触发");
-            // TODO: 实现点线距测量逻辑
+            _eventAggregator.GetEvent<MeasurementToolEvent>().Publish(MeasurementToolMode.PointLineDistance);
         }
 
         private void ExecuteAngleMeasure()

XplorePlane/Views/Main/ViewportPanelView.xaml.cs

@@ -26,7 +26,8 @@ namespace XplorePlane.Views
                 if (e is MeasureCompletedEventArgs args && DataContext is ViewportPanelViewModel vm)
                 {
                     vm.MeasurementResult = $"{args.Distance:F2} px";
-                    vm.ImageInfo = $"点点距: {args.Distance:F2} px | ({args.P1.X:F0},{args.P1.Y:F0}) → ({args.P2.X:F0},{args.P2.Y:F0}) | 共 {args.TotalCount} 条测量";
+                    string typeLabel = args.MeasureType == "PointToLine" ? "点线距" : "点点距";
+                    vm.ImageInfo = $"{typeLabel}: {args.Distance:F2} px | ({args.P1.X:F0},{args.P1.Y:F0}) → ({args.P2.X:F0},{args.P2.Y:F0}) | 共 {args.TotalCount} 条测量";
                 }
             };
             RoiCanvas.MeasureStatusChanged += (s, e) =>
@@ -47,7 +48,12 @@ namespace XplorePlane.Views
                 // 测量模式：直接订阅 Prism 事件
                 ea?.GetEvent<MeasurementToolEvent>().Subscribe(mode =>
                 {
-                    RoiCanvas.IsMeasuring = mode != MeasurementToolMode.None;
+                    RoiCanvas.CurrentMeasureMode = mode switch
+                    {
+                        MeasurementToolMode.PointDistance => XP.ImageProcessing.RoiControl.Models.MeasureMode.PointDistance,
+                        MeasurementToolMode.PointLineDistance => XP.ImageProcessing.RoiControl.Models.MeasureMode.PointToLine,
+                        _ => XP.ImageProcessing.RoiControl.Models.MeasureMode.None
+                    };
                 }, Prism.Events.ThreadOption.UIThread);
             }
             catch { }
@@ -63,12 +69,7 @@ namespace XplorePlane.Views
 
         private void OnVmPropertyChanged(object sender, PropertyChangedEventArgs e)
         {
-            if (sender is not ViewportPanelViewModel vm) return;
-
-            if (e.PropertyName == nameof(ViewportPanelViewModel.CurrentMeasurementMode))
-            {
-                RoiCanvas.IsMeasuring = vm.CurrentMeasurementMode != MeasurementToolMode.None;
-            }
+            // 测量模式和十字线通过 Prism 事件直接驱动，不再依赖 PropertyChanged
         }
 
         #region 右键菜单