用Wpf做一个画笔画板（续5-Diagram画板）

先上效果图吧

同样老规矩，先上源码地址：https://gitee.com/akwkevin/aistudio.-wpf.-diagram

本次实现的内容有

• [1] 画笔实现
• [2] 封闭画笔实现
• [3] 钢笔实现
• [4] 文字画笔
• [5] 直线，矩形，椭圆
• [6] Path形状
• [7] 取色器
• [8] 三种画笔可选

画笔示例入口

 示例截图

 核心代码：

1.Ellipse的实现：Geometry = new EllipseGeometry(new Rect(Points[0], Points[1]));

2.Rectangle的实现：   Geometry = new RectangleGeometry(new Rect(Points[0], Points[1]));

3.Line的实现：  Geometry = new LineGeometry(Points[0], Points[1]);

4.文本的实现：

var formattedText = new FormattedText(Text,
System.Globalization.CultureInfo.InvariantCulture,
FlowDirection.LeftToRight,
typeface,
FontViewModel.FontSize,
new SolidColorBrush(FontViewModel.FontColor));

Geometry = formattedText.BuildGeometry(new Point()).GetFlattenedPathGeometry();

5.多点连接线 

var geometry = new PathGeometry();
var figure = new PathFigure { StartPoint = Points[0] };
geometry.Figures.Add(figure);

for (int i = 1; i < Points.Count; i++)
{
LineSegment arc = new LineSegment(Points[i], true);
geometry.Figures[0].Segments.Add(arc);
}

Geometry = geometry;

6.Path形状

var path = GetPath();
PathGeometry pathGeometry = PathGeometry.CreateFromGeometry(Geometry.Parse(path));
var transformGroup = new TransformGroup();
double radiox = Math.Abs(Points[1].X - Points[0].X) / pathGeometry.Bounds.Width;
double radioy = Math.Abs(Points[1].Y - Points[0].Y) / pathGeometry.Bounds.Height;
transformGroup.Children.Add(new TranslateTransform((Points[0].X) / radiox - pathGeometry.Bounds.Left, (Points[0].Y) / radioy - pathGeometry.Bounds.Top));
transformGroup.Children.Add(new ScaleTransform(radiox, radioy));
pathGeometry.Transform = transformGroup;
Geometry = pathGeometry;

7.橡皮的实现

erase.Transform = new TranslateTransform(0 - Left, 0 - Top);

Geometry = Geometry.Combine(Geometry, erase, GeometryCombineMode.Exclude, null);

8.取色器的实现

var point = CursorPointManager.GetCursorPosition();
Root.CurrentColor = ColorPickerManager.GetColor(point.X, point.Y);

讲一个关键点：形状要可擦除，必须要转换一下

Geometry = Geometry.GetWidenedPathGeometry(aPen); 

今天实在有点懒得搞，就这样吧。