用C#绘制坐标轴及坐标轴刻度

用C#绘制坐标轴及坐标轴刻度

private void DrawXY(Bitmap bmp)
{
    /* 描绘坐标轴函数 */
    Graphics g = Graphics.FromImage(bmp); /* 利用图片对象生成画板 */
    Pen pAxis = new Pen(Brushes.Black, 2);

    AdjustableArrowCap aac = new AdjustableArrowCap(5, 10); /* 定义可调箭头 */
    pAxis.CustomEndCap = aac;

    /* 整体内缩move像素 */
    float move = 50f;
    float newX = bmp.Width - move;
    float newY = bmp.Height - move;

    /* 绘制X轴 */
    PointF px1 = new PointF(move + 30f, newY);
    PointF px2 = new PointF(newX, newY);
    g.DrawLine(pAxis, px1, px2);

    /* 绘制Y轴 */
    PointF py1 = new PointF(move + 30f, move);
    PointF py2 = new PointF(move + 30f, newY);

    g.DrawLine(pAxis, py2, py1);

}

public static float[] DrawXLine(Bitmap bmp, double minX, double maxX, int len, int n) // 画出X轴上的刻度线，从任意值开始
{
    Graphics g = Graphics.FromImage(bmp); 
    Pen pAxis = new Pen(Brushes.Black, 2);

    float move = 50f;
    float LenX = bmp.Width - 4 * move;
    float[] axis = new float[len + 1]; /* 用于存储X坐标 */

    for (int i = 0; i <= len; i++)
    {
        axis[i] = LenX * i / len + move + 50 + 15f;
        PointF py1 = new PointF(axis[i], bmp.Height - move - 4);
        PointF py2 = new PointF(axis[i], bmp.Height - move);
        string sy = ((maxX - minX) * i / len + minX).ToString(tag);
        g.DrawLine(pAxis, py1, py2);
        int temp = 40; /* 坐标轴刻度字符的偏移量 */
        switch (sy.Length)
        {
            /* 根据字符的位数不同设置不同的偏移量 */
            case 1:
                temp = 45; break;
            case 2:
                temp = 42; break;
            case 3:
                temp = 40; break;
            case 4:
                temp = 37; break;
            case 5:
                temp = 35; break;
            case 6:
                temp = 33; break;
            case 7:
                temp = 31; break;
            case 8:
                temp = 29; break;
            case 9:
                temp = 27; break;
            case 10:
                temp = 25; break;
            case 11:
                temp = 23; break;
            default:
                break;
        }
        g.DrawString(sy, new Font("宋体", 8f), Brushes.Black, 
            new PointF(LenX * i / len + move + 15f + temp, bmp.Height - move / 1.1f));
    }

    Pen pen = new Pen(Color.Black, 1);
    string str = "时间";
    
    g.DrawString(str, new Font("宋体", 10f), Brushes.Black, 
        new PointF(bmp.Width - 10 * move / 1.5f - 100, bmp.Height - move / 1.5f + 5f));
    g.Dispose();
    return axis;
}

public static void DrawYLine(Bitmap bmp, double minY, double maxY, int len, int n) // 画出Y轴上的刻度线，从任意值开始
{
    /* len表示刻度间隔数目 */
    Graphics g = Graphics.FromImage(bmp); 
    Pen pAxis = new Pen(Brushes.Black, 2);

    float move = 50f;
    float LenY = bmp.Height - 4 * move;
    float tempY;

    for (int i = len; i >= 0; i--)    
    {
        tempY = LenY * i / len + move + 50;
        PointF px1 = new PointF(move + 30f, tempY);
        PointF px2 = new PointF(move + 30f + 4, tempY);
        string sx = (maxY - (maxY - minY) * (len - i) / len).ToString(tag);
        g.DrawLine(pAxis, px1, px2);
        StringFormat drawFormat = new StringFormat();
        drawFormat.Alignment = StringAlignment.Far;
        drawFormat.LineAlignment = StringAlignment.Center;
        g.DrawString(sx, new Font("宋体", 8f), Brushes.Black, 
            new PointF(move / 1.2f + 30f, tempY), drawFormat);
    }
    Pen pen = new Pen(Color.Black, 1);
    string str = "位移";
    g.DrawString(str, new Font("宋体", 10f), Brushes.Black, new PointF(move / 3, move / 2f));
    g.Dispose();
}