add:插件系统

Plugins/Samples/SampleClockPlugin/ClockOverlayPlugin.cs

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+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+using System.Windows.Threading;
+using InkCanvasForClass.PluginSdk;
+
+namespace InkCanvasForClass.SamplePlugins
+{
+    /// <summary>
+    /// 示例插件：在当前 <see cref="InkCanvas"/> 右上角叠加显示实时时钟（不拦截笔触命中）。
+    /// </summary>
+    public sealed class ClockOverlayPlugin : InkCanvasPluginBase
+    {
+        public override string Id => "inkcanvas.sample.clock-overlay";
+
+        public override string Name => "画布时钟示例";
+
+        public override string Description => "在画布右上角显示当前时间（HH:mm:ss）";
+
+        public override Version Version => new Version(1, 0, 0);
+
+        public override string Author => "ICC CE Sample";
+
+        private Border _host;
+        private TextBlock _timeText;
+        private DispatcherTimer _timer;
+        private System.Windows.Controls.InkCanvas _canvas;
+        private SizeChangedEventHandler _sizeHandler;
+
+        public override void Start()
+        {
+            base.Start();
+
+            var mw = Context?.MainWindow;
+            var canvas = Context?.CurrentCanvas as System.Windows.Controls.InkCanvas;
+            if (mw == null || canvas == null)
+            {
+                return;
+            }
+
+            mw.Dispatcher.Invoke(() =>
+            {
+                _canvas = canvas;
+                _host = new Border
+                {
+                    Background = new SolidColorBrush(Color.FromArgb(170, 32, 32, 36)),
+                    CornerRadius = new CornerRadius(8),
+                    Padding = new Thickness(12, 8, 12, 8),
+                    IsHitTestVisible = false
+                };
+                _timeText = new TextBlock
+                {
+                    FontSize = 24,
+                    FontWeight = FontWeights.SemiBold,
+                    Foreground = Brushes.White,
+                    FontFamily = new FontFamily("Segoe UI, Microsoft YaHei UI")
+                };
+                _host.Child = _timeText;
+                Panel.SetZIndex(_host, 10050);
+
+                _canvas.Children.Add(_host);
+                _sizeHandler = (s, e) => Reposition();
+                _canvas.SizeChanged += _sizeHandler;
+                Reposition();
+
+                _timer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(1) };
+                _timer.Tick += (_, __) => Tick();
+                _timer.Start();
+                Tick();
+            });
+        }
+
+        private void Tick()
+        {
+            if (_timeText != null)
+            {
+                _timeText.Text = DateTime.Now.ToString("HH:mm:ss");
+            }
+        }
+
+        private void Reposition()
+        {
+            if (_canvas == null || _host == null)
+            {
+                return;
+            }
+
+            _host.UpdateLayout();
+            var left = Math.Max(8, _canvas.ActualWidth - _host.ActualWidth - 20);
+            InkCanvas.SetLeft(_host, left);
+            InkCanvas.SetTop(_host, 20);
+        }
+
+        public override void Stop()
+        {
+            var mw = Context?.MainWindow;
+            if (mw != null && (_canvas != null || _host != null))
+            {
+                mw.Dispatcher.Invoke(() =>
+                {
+                    try
+                    {
+                        if (_timer != null)
+                        {
+                            _timer.Stop();
+                            _timer = null;
+                        }
+
+                        if (_canvas != null && _sizeHandler != null)
+                        {
+                            _canvas.SizeChanged -= _sizeHandler;
+                            _sizeHandler = null;
+                        }
+
+                        if (_canvas != null && _host != null && _canvas.Children.Contains(_host))
+                        {
+                            _canvas.Children.Remove(_host);
+                        }
+                    }
+                    catch
+                    {
+                        // 避免卸载时异常影响宿主
+                    }
+                    finally
+                    {
+                        _host = null;
+                        _timeText = null;
+                        _canvas = null;
+                    }
+                });
+            }
+
+            base.Stop();
+        }
+    }
+}

Plugins/Samples/SampleClockPlugin/SampleClockPlugin.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net472</TargetFramework>
+    <RootNamespace>InkCanvasForClass.SamplePlugins</RootNamespace>
+    <AssemblyName>SampleClockPlugin</AssemblyName>
+    <UseWPF>true</UseWPF>
+    <LangVersion>7.3</LangVersion>
+    <Nullable>disable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\SDK\InkCanvas.PluginSdk.csproj" />
+  </ItemGroup>
+
+</Project>