标记多边形

Question

我有一个函数可以用来创建一个点数组，所以我可以绘制一个多边形，我想在这个多边形内部添加标签，我知道可以使用 drawstring 或 label control 来完成，但我想确保我的多边形方向相同，在我的情况下，它们是矩形，还根据形状大小控制字体大小。

我试图在 Draw 字符串中创建一个 rect 没有成功，任何想法

 private void BuildImage()
    {
        Graphics refGraph = this.CreateGraphics();
        IntPtr hdc = refGraph.GetHdc();
        Metafile image = new Metafile(hdc, EmfType.EmfOnly, "Shapes");
        using (var g = Graphics.FromImage(image))
        {
            g.SmoothingMode = SmoothingMode.AntiAlias;
            SolidBrush myBrush = new SolidBrush(Color.Black);
            Pen p = new Pen(Color.Red, 0.2f);
            foreach (CircuitData.ResistorRow resistorRow in ResistorData.Resistor)
            {
                RectangleF rec = new RectangleF((float)(resistorRow.CenterX - resistorRow.Length / 2), (float)(resistorRow.CenterY - resistorRow.Width / 2), (float)resistorRow.Length, (float)resistorRow.Width);
                float orientation = 360 - (float)resistorRow.Orientation;
                PointF center = new PointF((float)resistorRow.CenterX, (float)resistorRow.CenterY);
                PointF[] points = CreatePolygon(rec, center, orientation);
                if (!Double.IsNaN(resistorRow.HiX) && !Double.IsNaN(resistorRow.HiY))
                {
                    g.FillEllipse(myBrush, (float)resistorRow.HiX - 0.5f, (float)resistorRow.HiY - 0.5f, 1, 1);
                    g.DrawLine(p, new PointF((float)resistorRow.HiX, (float)resistorRow.HiY), center);
                }

                g.FillPolygon(myBrush, points);

                Font drawFont = new Font("cursor", 1);
                SolidBrush textBrush = new SolidBrush(Color.Blue);
                //g.Transform = matrix;
                g.DrawString(resistorRow.ComponentName, drawFont, textBrush, points[0]);
            }
        }
        refGraph.ReleaseHdc(hdc);
        refGraph.Dispose();
        Image = image;

    }


private PointF[] CreatePolygon(RectangleF rec, PointF center, float orientation)
        {
            PointF TL = new PointF(rec.Left, rec.Top);
            PointF TR = new PointF(rec.Right, rec.Top);
            PointF BL = new PointF(rec.Left, rec.Bottom);
            PointF BR = new PointF(rec.Right, rec.Bottom);
            PointF[] points = new PointF[] { BL, TL, TR, BR, BL };
            matrix = new System.Drawing.Drawing2D.Matrix();
            matrix.RotateAt(orientation, center);
            matrix.TransformPoints(points);
            return points;
        }

Answer 1

将旋转矩阵应用于您正在使用的图形上下文：

        e.Graphics.Transform = matrix;
        e.Graphics.FillPolygon(textBrush, points);
        e.Graphics.DrawString(resistorRow.ComponentName, drawFont, textBrush2, TL);

编辑：一些样本代码：

public class ResistorWithLabel
{
    public string ComponentName { get; set; }
    public RectangleF Rect { get; set; }
    public float Orientation { get; set; }
    public Color BackgroundColor { get; set; }
    public Color ForegroundColor { get; set; }
    public int FontSize { get; set; }

    public void Draw(Graphics g)
    {
        Matrix contextMatrix = g.Transform;
        Matrix matrix = new Matrix();
        matrix.RotateAt(Orientation, new PointF((Rect.Left+Rect.Right)/2, (Rect.Top+Rect.Bottom)/2));

        SolidBrush polygonBrush = new SolidBrush(BackgroundColor);
        SolidBrush textBrush = new SolidBrush(ForegroundColor);
        Font font = new Font("Courier", FontSize);

        PointF TL = new PointF(Rect.Left, Rect.Top);
        PointF TR = new PointF(Rect.Right, Rect.Top);
        PointF BL = new PointF(Rect.Left, Rect.Bottom);
        PointF BR = new PointF(Rect.Right, Rect.Bottom);
        PointF[] points = new PointF[] { BL, TL, TR, BR };

        g.Transform = matrix;
        g.FillPolygon(polygonBrush, points);
        g.DrawString(ComponentName, font, textBrush, TL);
        g.Transform = contextMatrix;
    }
}

    private void Form3_Paint(object sender, PaintEventArgs e)
    {
        ResistorWithLabel r1 = new ResistorWithLabel();
        r1.ComponentName = "Resistor 1";
        r1.Rect = new RectangleF(50, 100, 100, 50);
        r1.Orientation = 25;
        r1.BackgroundColor = Color.Blue;
        r1.ForegroundColor = Color.Yellow;
        r1.FontSize = 16;
        r1.Draw(e.Graphics);

        ResistorWithLabel r2 = new ResistorWithLabel();
        r2.ComponentName = "Resistor 2";
        r2.Rect = new RectangleF(200, 100, 200, 100);
        r2.Orientation = 75;
        r2.BackgroundColor = Color.Gray;
        r2.ForegroundColor = Color.Orange;
        r2.FontSize = 32;
        r2.Draw(e.Graphics);
    }

标记多边形

Label a polygon

c#

graphics

polygon

winforms