在DrawingFrame上繪製線條與外線

Question

我試圖在WPF中繪製很多類似的線條，如this問題所示，但不同之處在於我需要將它繪製在DrawingVisual對象的DrawingContext上。如何做呢？

Answer 1

你將不得不在兩個相同的點之間畫兩條線，上下兩邊用較粗的筆，上邊用較薄的筆。

Pen background = new Pen(Brushes.Black, 5); 
Pen foreground = new Pen(Brushes.White, 3); 

drawingContext.DrawLine(background, new Point(100, 100), new Point(200, 200)); 
drawingContext.DrawLine(foreground, new Point(100, 100), new Point(200, 200)); 

此線看很多更好，當你還定義了筆線帽：

Pen background = new Pen 
{ 
    Brush = Brushes.Black, 
    Thickness = 5, 
    StartLineCap = PenLineCap.Round, 
    EndLineCap = PenLineCap.Round 
}; 

Pen foreground = new Pen 
{ 
    Brush = Brushes.White, 
    Thickness = 3, 
    StartLineCap = PenLineCap.Round, 
    EndLineCap = PenLineCap.Round 
}; 

有了這樣

public static class DrawingContextExtensions 
{ 
    public static void DrawLine(this DrawingContext drawingContext, 
     Pen background, Pen foreground, Point start, Point end) 
    { 
     drawingContext.DrawLine(background, start, end); 
     drawingContext.DrawLine(foreground, start, end); 
    } 
} 

擴展方法，你可以做圖中的一個呼叫：

drawingContext.DrawLine(background, foreground, new Point(100, 100), new Point(200, 200));