支持画笔及痕迹擦除，为白板做准备

AIStudio.Wpf.DiagramDesigner/ViewModels/AdditionViewModel/ColorViewModel.cs

@@ -8,6 +8,7 @@ using System.Threading;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Media;
+using System.Windows.Media.Imaging;
 
 namespace AIStudio.Wpf.DiagramDesigner
 {
@@ -126,7 +127,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     RaisePropertyChanged(nameof(LineWidth));
                 }
             }
-        }       
+        }
 
         private LineDashStyle _lineDashStyle = LineDashStyle.None;
         [CanDo]
@@ -221,8 +222,6 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             set
             {
-                var xx = this.GetHashCode();
-                var yy = Thread.CurrentThread.ManagedThreadId.ToString();
                 SetProperty(ref _color, value);
             }
         }
@@ -391,8 +390,7 @@ namespace AIStudio.Wpf.DiagramDesigner
         {
             get
             {
-                return new SimpleCommand(para =>
-                {
+                return new SimpleCommand(para => {
                     var offset = GradientStop.Skip(GradientStop.Count - 2).Select(p => p.Offset).Average();
                     GradientStop.Add(new GradientStop(Colors.Gray, offset));
                 });
@@ -402,8 +400,7 @@ namespace AIStudio.Wpf.DiagramDesigner
         {
             get
             {
-                return new SimpleCommand(para =>
-                {
+                return new SimpleCommand(para => {
                     if (SelectedGradientStop != null && GradientStop != null && GradientStop.Count > 2)
                     {
                         GradientStop.Remove(SelectedGradientStop);
@@ -411,21 +408,231 @@ namespace AIStudio.Wpf.DiagramDesigner
                 });
             }
         }
+
+        public static Brush ToBrush(IColorObject colorObject)
+        {
+            Brush brush = null;
+
+            if (colorObject.BrushType == BrushType.None)
+                brush = new SolidColorBrush(Colors.Transparent);
+            else if (colorObject.BrushType == BrushType.SolidColorBrush)
+                brush = new SolidColorBrush(colorObject.Color);
+            else if (colorObject.BrushType == BrushType.LinearGradientBrush)
+            {
+                Point startPoint;
+                Point endPoint;
+                if (colorObject.LinearOrientation == LinearOrientation.LeftToRight)
+                {
+                    startPoint = new Point(0, 0.5);
+                    endPoint = new Point(1, 0.5);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.LeftTopToRightBottom)
+                {
+                    startPoint = new Point(0, 0);
+                    endPoint = new Point(1, 1);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.TopToBottom)
+                {
+                    startPoint = new Point(0.5, 0);
+                    endPoint = new Point(0.5, 1);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.RightTopToLeftBottom)
+                {
+                    startPoint = new Point(1, 0);
+                    endPoint = new Point(0, 1);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.RightToLeft)
+                {
+                    startPoint = new Point(1, 0.5);
+                    endPoint = new Point(0, 0.5);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.RightBottomToLeftTop)
+                {
+                    startPoint = new Point(1, 1);
+                    endPoint = new Point(0, 0);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.BottomToTop)
+                {
+                    startPoint = new Point(0.5, 1);
+                    endPoint = new Point(0.5, 0);
+                }
+                else if (colorObject.LinearOrientation == LinearOrientation.LeftBottomToRightTop)
+                {
+                    startPoint = new Point(0, 1);
+                    endPoint = new Point(1, 0);
+                }
+                else
+                {
+                    startPoint = new Point(0, 0.5);
+                    endPoint = new Point(1, 0.5);
+                }
+
+                LinearGradientBrush myBrush = new LinearGradientBrush();
+                myBrush.StartPoint = startPoint;
+                myBrush.EndPoint = endPoint;
+                if (colorObject.GradientStop != null)
+                {
+                    foreach (var stop in colorObject.GradientStop)
+                    {
+                        myBrush.GradientStops.Add(new System.Windows.Media.GradientStop(stop.Color, stop.Offset));
+                    }
+                }
+                brush = myBrush;
+
+                RotateTransform rotateTransform = new RotateTransform(colorObject.Angle, 0.5, 0.5);
+                myBrush.RelativeTransform = rotateTransform;
+            }
+            else if (colorObject.BrushType == BrushType.RadialGradientBrush)
+            {
+                Point center;
+                Point gradientOrigin;
+                double radiusX;
+                double radiusY;
+
+                if (colorObject.RadialOrientation == RadialOrientation.LeftTop)
+                {
+                    center = new Point(0, 0);
+                    gradientOrigin = center;
+                    radiusX = 1;
+                    radiusY = 1;
+                }
+                else if (colorObject.RadialOrientation == RadialOrientation.RightTop)
+                {
+                    center = new Point(1, 0);
+                    gradientOrigin = center;
+                    radiusX = 1;
+                    radiusY = 1;
+                }
+                else if (colorObject.RadialOrientation == RadialOrientation.RightBottom)
+                {
+                    center = new Point(1, 1);
+                    gradientOrigin = center;
+                    radiusX = 1;
+                    radiusY = 1;
+                }
+                else if (colorObject.RadialOrientation == RadialOrientation.LeftBottom)
+                {
+                    center = new Point(0, 1);
+                    gradientOrigin = center;
+                    radiusX = 1;
+                    radiusY = 1;
+                }
+                else
+                {
+                    center = new Point(0.5, 0.5);
+                    gradientOrigin = center;
+                    radiusX = 0.5;
+                    radiusY = 0.5;
+                }
+
+                RadialGradientBrush myBrush = new RadialGradientBrush();
+                myBrush.Center = center;
+                myBrush.GradientOrigin = gradientOrigin;
+                myBrush.RadiusX = radiusX;
+                myBrush.RadiusY = radiusY;
+                if (colorObject.GradientStop != null)
+                {
+                    foreach (var stop in colorObject.GradientStop)
+                    {
+                        myBrush.GradientStops.Add(new System.Windows.Media.GradientStop(stop.Color, stop.Offset));
+                    }
+                }
+                brush = myBrush;
+
+                RotateTransform rotateTransform = new RotateTransform(colorObject.Angle, 0.5, 0.5);
+                myBrush.RelativeTransform = rotateTransform;
+            }
+            else if (colorObject.BrushType == BrushType.ImageBrush)
+            {
+                ImageBrush myBrush = new ImageBrush();
+                myBrush.ImageSource = new BitmapImage(new Uri(colorObject.Image, UriKind.Absolute));
+                brush = myBrush;
+            }
+            else if (colorObject.BrushType == BrushType.DrawingBrush)
+            {
+                DrawingBrush myBrush = new DrawingBrush();
+
+                GeometryDrawing backgroundSquare =
+                    new GeometryDrawing(
+                        Brushes.White,
+                        null,
+                        new RectangleGeometry(new Rect(0, 0, 100, 100)));
+
+                GeometryGroup aGeometryGroup = new GeometryGroup();
+                aGeometryGroup.Children.Add(new RectangleGeometry(new Rect(0, 0, 50, 50)));
+                aGeometryGroup.Children.Add(new RectangleGeometry(new Rect(50, 50, 50, 50)));
+
+                LinearGradientBrush checkerBrush = new LinearGradientBrush();
+                checkerBrush.GradientStops.Add(new System.Windows.Media.GradientStop(Colors.Black, 0.0));
+                checkerBrush.GradientStops.Add(new System.Windows.Media.GradientStop(Colors.Gray, 1.0));
+
+                GeometryDrawing checkers = new GeometryDrawing(checkerBrush, null, aGeometryGroup);
+
+                DrawingGroup checkersDrawingGroup = new DrawingGroup();
+                checkersDrawingGroup.Children.Add(backgroundSquare);
+                checkersDrawingGroup.Children.Add(checkers);
+
+                myBrush.Drawing = checkersDrawingGroup;
+                myBrush.Viewport = new Rect(0, 0, 0.25, 0.25);
+                myBrush.TileMode = TileMode.Tile;
+
+                brush = myBrush;
+            }
+            if (brush != null)
+            {
+                brush.Opacity = colorObject.Opacity;
+            }
+
+            return brush;
+        }
     }
 
     public interface IColorObject
     {
-        BrushType BrushType { get; set; }
-        Color Color { get; set; }
-        ObservableCollection<GradientStop> GradientStop { get; set; }
-        Point StartPoint { get; set; }
-        Point EndPoint { get; set; }
-        double Opacity { get; set; }
-        LinearOrientation LinearOrientation { get; set; }
-        RadialOrientation RadialOrientation { get; set; }
-        int Angle { get; set; }
-        string Image { get; set; }
-        int SubType { get; set; }
+        BrushType BrushType
+        {
+            get; set;
+        }
+        Color Color
+        {
+            get; set;
+        }
+        ObservableCollection<GradientStop> GradientStop
+        {
+            get; set;
+        }
+        Point StartPoint
+        {
+            get; set;
+        }
+        Point EndPoint
+        {
+            get; set;
+        }
+        double Opacity
+        {
+            get; set;
+        }
+        LinearOrientation LinearOrientation
+        {
+            get; set;
+        }
+        RadialOrientation RadialOrientation
+        {
+            get; set;
+        }
+        int Angle
+        {
+            get; set;
+        }
+        string Image
+        {
+            get; set;
+        }
+        int SubType
+        {
+            get; set;
+        }
     }
 
     public class GradientStop : BindableBase