创建用点填充的多边形

Question

正在使用下面的代码创建多边形。我只是想用黑点填充这个多边形表面，我如何做到这一点，然后我想将这个多边形转换为位图或内存流，如何做到这一点？

// Create a blue and a black Brush 
     SolidColorBrush yellowBrush = new SolidColorBrush(); 
     yellowBrush.Color = Colors.Transparent; 
     SolidColorBrush blackBrush = new SolidColorBrush(); 
     blackBrush.Color = Colors.Black; 

     // Create a Polygon 
     Polygon yellowPolygon = new Polygon(); 
     yellowPolygon.Stroke = blackBrush; 
     yellowPolygon.Fill = yellowBrush; 
     yellowPolygon.StrokeThickness = 4; 

     // Create a collection of points for a polygon 
     System.Windows.Point Point1 = new System.Windows.Point(50, 100); 
     System.Windows.Point Point2 = new System.Windows.Point(200, 100); 
     System.Windows.Point Point3 = new System.Windows.Point(200, 200); 
     System.Windows.Point Point4 = new System.Windows.Point(300, 30); 

     PointCollection polygonPoints = new PointCollection(); 
     polygonPoints.Add(Point1); 
     polygonPoints.Add(Point2); 
     polygonPoints.Add(Point3); 
     polygonPoints.Add(Point4); 

     // Set Polygon.Points properties 
     yellowPolygon.Points = polygonPoints;   

     // Add Polygon to the page 
     mygrid.Children.Add(yellowPolygon); 

Answer 1

点是否必须按特定顺序排列，或者您只是想在没有特定顺序的情况下在多边形中使用点状图案？

如果你不需要一个特殊的订单，你可以使用一个刷子，一个DrawingBrush例如。看看这个链接：http://msdn.microsoft.com/en-us/library/aa970904.aspx

然后，您可以将此画笔设置为多边形的填充属性而不是SolidColorBrush。

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这是从MSDN链接DrawingBrush例子，但修改以显示点：

// Create a DrawingBrush and use it to 
// paint the rectangle. 
DrawingBrush myBrush = new DrawingBrush(); 

GeometryDrawing backgroundSquare = 
    new GeometryDrawing(
     Brushes.Yellow, 
     null, 
     new RectangleGeometry(new Rect(0, 0, 100, 100))); 

GeometryGroup aGeometryGroup = new GeometryGroup(); 
aGeometryGroup.Children.Add(new EllipseGeometry(new Rect(0, 0, 20, 20))); 

SolidColorBrush checkerBrush = new SolidColorBrush(Colors.Black); 

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, 0.05, 0.05); 
myBrush.TileMode = TileMode.Tile; 

yellowPolygon.Fill = myBrush;