Question

我需要生成一个新方法来填充下面的代码中的三角形并分别调用有什么建议吗？

public void draw(Graphics g, Pen blackPen)
    {
        double xDiff, yDiff, xMid, yMid;

        xDiff = oppPt.X - keyPt.X;
        yDiff = oppPt.Y - keyPt.Y;
        xMid = (oppPt.X + keyPt.X) / 2;
        yMid = (oppPt.Y + keyPt.Y) / 2;

        // draw triangle
        g.DrawLine(blackPen, (int)keyPt.X, (int)keyPt.Y, (int)(xMid + yDiff / 2), (int)(yMid - xDiff / 2));
        g.DrawLine(blackPen, (int)(xMid + yDiff / 2), (int)(yMid - xDiff / 2), (int)oppPt.X, (int)oppPt.Y);
        g.DrawLine(blackPen, (int)keyPt.X, (int)keyPt.Y, oppPt.X, oppPt.Y);

    }

该方法应同时使用这两个参数

public void fillTriangle(Graphics g, Brush redBrush)
    {


    }

Answer 1

对图形使用单个函数，为降低复杂性和一致性，请使用GraphicsPath对象。

void DrawGraphics(Graphics g, Pen pen, Brush brush)
{
    float xDiff=oppPt.X-keyPt.X;
    float yDiff=oppPt.Y-keyPt.Y;
    float xMid=(oppPt.X+keyPt.X)/2;
    float yMid=(oppPt.Y+keyPt.Y)/2;

    // Define path with the geometry information only
    var path = new GraphicsPath();
    path.AddLines(new PointF[] {
        keyPt,
        new PointF(xMid + yDiff/2, yMid-xDiff/2),
        oppPt,
    });
    path.CloseFigure();

    // Fill Triangle
    g.FillPath(brush, path);

    // Draw Triangle
    g.DrawPath(pen, path);
}

结果如下所示：

Answer 2

您只需要创建一个带有点的数组，然后配置填充方式，然后是绘制FillPolygon，它是实体DrawPolygon的轮廓。

    public void draw(Pen blackPen)
    {
        Graphics draw = CreateGraphics();

        Point[] points = new Point[6];
        points[0].X = 0;
        points[0].Y = 0;
        points[1].X = 150;
        points[1].Y = 150;
        points[2].X = 0;
        points[2].Y = 150;

        using (SolidBrush fillvar = new SolidBrush(Color.FromArgb(100, Color.Yellow)))
        {
            draw.FillPolygon(fillvar, points.ToArray());
            draw.DrawPolygon(Pens.DarkBlue, points);
        }

    }

如果要将FillPolygon绘制在某物内部，例如PictureBox，则只需将其分配给Graphics draw。

    Graphics draw = picturebox.CreateGraphics();

以上只是有关其工作原理的实际说明，请看一下您的代码。缺少只是实现其xDiff，yiff，xMid，yMid坐标。

    public void draw(Graphics g, Pen blackPen)
    {
        double xDiff, yDiff, xMid, yMid;

        Point[] points = new Point[6];
        points[0].X = 50;
        points[0].Y = 50;
        points[1].X = 150;
        points[1].Y = 150;
        points[2].X = 0;
        points[2].Y = 150;

        SolidBrush varbrush = new SolidBrush(Color.FromArgb(100, Color.Yellow));

        fillTriangle(g, varbrush, points);
    }

您必须将点传递到fillTriangle并以这种方法绘制它们。

    public void fillTriangle(Graphics g, Brush varbrush, Point[] points)
    {
        g.FillPolygon(varbrush, points.ToArray());
        g.DrawPolygon(Pens.Red, points);
    }

使用线条填充绘制的三角形

2 个答案: