C#绘制阻抗圆图初步

阻抗圆图，或者叫史密斯图，是无线电设计方面用的；

基本的阻抗圆图如下，

下面尝试用C#能不能画一下；

先在网上找一个画坐标的C#类，它的效果如下；

自己再增加一个函数，可以绘制中心在画布中心的坐标系；

看一下基本的阻抗圆图，它有4个圆；先把4个圆画一下如下，

那几条曲线不知道怎么画，不知道是什么曲线，用什么函数描述； 有时间继续；

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Drawing2D;namespace commengineer
{public static class XYlinesFactory{#region   画出X轴与Y轴/// <summary>  /// 在任意的panel里画一个坐标，坐标所在的四边形距离panel边50像素  /// </summary>  /// <param name="pan"></param>  public static void DrawXY(Panel pan){Graphics g = pan.CreateGraphics();//整体内缩move像素  float move = 50f;float newX = pan.Width - move;float newY = pan.Height - move;//绘制X轴,  PointF px1 = new PointF(move, newY);PointF px2 = new PointF(newX, newY);g.DrawLine(new Pen(Brushes.Black, 2), px1, px2);//绘制Y轴  PointF py1 = new PointF(move, move);PointF py2 = new PointF(move, newY);g.DrawLine(new Pen(Brushes.Black, 2), py1, py2);}#endregionpublic static void DrawCXY(Panel pan){Graphics g = pan.CreateGraphics();//整体内缩move像素  float move = 50f;float newX = pan.Width - move;float newY = pan.Height - move;float x1 = move / 2;float x2 = move / 2 + newX;float y1 = newY / 2 + move/2;PointF p1 = new PointF(x1, y1);PointF p2 = new PointF(x2, y1);PointF p3 = new PointF(move/2 + newX/2, move/2);PointF p4 = new PointF(move / 2 + newX / 2, pan.Height - move/2);g.DrawLine(new Pen(Brushes.Black, 1), p1, p2);g.DrawLine(new Pen(Brushes.Black, 1), p3, p4);}public static void DrawSmithCircle(Panel pan){Graphics g = pan.CreateGraphics();float bound = 50f;float centerX = pan.Width / 2;float centery = pan.Height / 2;float scr1 = ((pan.Width - bound) /2) * 0.8f;float scr2 = (scr1 + scr1 / 2) / 2;float scr3 = scr1 / 2;float scr4 = scr3 / 2;//float r1 = ((pan.Width - 50f) / 2) * 0.8f;//GraphicsPath circlePath = new GraphicsPath();//circlePath.AddEllipse(pan.Width/2, pan.Height/2, r1, r1);// 设置画笔和填充色//Brush brush = Brushes.Blue;// 绘制圆g.DrawEllipse(new Pen(Brushes.Black, 1), centerX - scr1, centery - scr1, scr1*2, scr1*2);g.DrawEllipse(new Pen(Brushes.Black, 1), centerX - scr1/2, centery - scr2, scr2 * 2, scr2 * 2);g.DrawEllipse(new Pen(Brushes.Black, 1), centerX, centery - scr3, scr3 * 2, scr3 * 2);g.DrawEllipse(new Pen(Brushes.Black, 1), centerX+scr3, centery - scr4, scr4 * 2, scr4 * 2);//g.FillPath(brush, circlePath);}/// <summary>  /// 画出Y轴上的分值线，从零开始  /// </summary>  /// <param name="pan"></param>  /// <param name="maxY"></param>  /// <param name="len"></param>  #region   画出Y轴上的分值线，从零开始public static void DrawYLine(Panel pan, float maxY, int len){float move = 50f;float LenX = pan.Width - 2 * move;float LenY = pan.Height - 2 * move;Graphics g = pan.CreateGraphics();for (int i = 0; i <= len; i++)    //len等份Y轴  {PointF px1 = new PointF(move, LenY * i / len + move);PointF px2 = new PointF(move + 4, LenY * i / len + move);string sx = (maxY - maxY * i / len).ToString();g.DrawLine(new Pen(Brushes.Black, 2), 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, LenY * i / len + move * 1.1f), drawFormat);}Pen pen = new Pen(Color.Black, 1);g.DrawString("Y轴", new Font("宋体 ", 10f), Brushes.Black, new PointF(move / 3, move / 2f));}#endregion/// <summary>  /// 画出Y轴上的分值线，从任意值开始  /// </summary>  /// <param name="pan"></param>  /// <param name="minY"></param>  /// <param name="maxY"></param>  /// <param name="len"></param>  #region   画出Y轴上的分值线，从任意值开始public static void DrawYLine(Panel pan, float minY, float maxY, int len){float move = 50f;float LenX = pan.Width - 2 * move;float LenY = pan.Height - 2 * move;Graphics g = pan.CreateGraphics();for (int i = 0; i <= len; i++)    //len等份Y轴  {PointF px1 = new PointF(move, LenY * i / len + move);PointF px2 = new PointF(move + 4, LenY * i / len + move);string sx = (maxY - (maxY - minY) * i / len).ToString();g.DrawLine(new Pen(Brushes.Black, 2), 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, LenY * i / len + move * 1.1f), drawFormat);}Pen pen = new Pen(Color.Black, 1);g.DrawString("Y轴", new Font("宋体 ", 10f), Brushes.Black, new PointF(move / 3, move / 2f));}#endregion/// <summary>  /// 画出X轴上的分值线，从零开始  /// </summary>  /// <param name="pan"></param>  /// <param name="maxX"></param>  /// <param name="len"></param>  #region   画出X轴上的分值线，从零开始public static void DrawXLine(Panel pan, float maxX, int len){float move = 50f;float LenX = pan.Width - 2 * move;float LenY = pan.Height - 2 * move;Graphics g = pan.CreateGraphics();for (int i = 1; i <= len; i++){PointF py1 = new PointF(LenX * i / len + move, pan.Height - move - 4);PointF py2 = new PointF(LenX * i / len + move, pan.Height - move);string sy = (maxX * i / len).ToString();g.DrawLine(new Pen(Brushes.Black, 2), py1, py2);g.DrawString(sy, new Font("宋体", 8f), Brushes.Black, new PointF(LenX * i / len + move, pan.Height - move / 1.1f));}Pen pen = new Pen(Color.Black, 1);g.DrawString("X轴", new Font("宋体 ", 10f), Brushes.Black, new PointF(pan.Width - move / 1.5f, pan.Height - move / 1.5f));}#endregion#region   画出X轴上的分值线，从任意值开始/// <summary>  /// 画出X轴上的分值线，从任意值开始  /// </summary>  /// <param name="pan"></param>  /// <param name="minX"></param>  /// <param name="maxX"></param>  /// <param name="len"></param>  public static void DrawXLine(Panel pan, float minX, float maxX, int len){float move = 50f;float LenX = pan.Width - 2 * move;float LenY = pan.Height - 2 * move;Graphics g = pan.CreateGraphics();for (int i = 0; i <= len; i++){PointF py1 = new PointF(LenX * i / len + move, pan.Height - move - 4);PointF py2 = new PointF(LenX * i / len + move, pan.Height - move);string sy = ((maxX - minX) * i / len + minX).ToString();g.DrawLine(new Pen(Brushes.Black, 2), py1, py2);g.DrawString(sy, new Font("宋体", 8f), Brushes.Black, new PointF(LenX * i / len + move, pan.Height - move / 1.1f));}Pen pen = new Pen(Color.Black, 1);g.DrawString("X轴", new Font("宋体 ", 10f), Brushes.Black, new PointF(pan.Width - move / 1.5f, pan.Height - move / 1.5f));}#endregion  }
}

调用代码；

        private void toolStripMenuItem2_Click(object sender, EventArgs e){//XYlinesFactory.DrawXY(panel1);//XYlinesFactory.DrawXLine(panel1, 100.00f, 12);//XYlinesFactory.DrawYLine(panel1, 100.00f, 12);XYlinesFactory.DrawCXY(panel1);XYlinesFactory.DrawSmithCircle(panel1);}private void Form8_Load(object sender, EventArgs e){panel1.Width = 600;panel1.Height = 600;}

看了一点资料，这图上都是圆；曲线的那几根是圆弧，是圆的一部分；

把圆在脑子里想出来，按照C#画弧的方式，只画出圆的一部分；加上如下四句画弧的代码，

            g.DrawArc(new Pen(Brushes.Black, 1), centerX,centery-scr1*2, scr1*2,scr1*2,  90, 90);g.DrawArc(new Pen(Brushes.Black, 1), centerX, centery, scr1 * 2, scr1 * 2, 180, 90);g.DrawArc(new Pen(Brushes.Black, 1), centerX-scr1/2, centery-scr2*3, scr2 * 3, scr2 * 3, 90, 78);g.DrawArc(new Pen(Brushes.Black, 1), centerX - scr1 / 2, centery, scr2 * 3, scr2 * 3, 192, 78);

效果如下，

还没完全理解它的规律；

所取的画弧的正方形的边长分别是scr1 * 2,   scr2*3，转78的角度也是大致试出来的；

scr1是最大圆的半径，scr2是第二大圆的半径；

g.DrawArc()的第一个参数是画笔，接下来2个参数是画弧参照正方形的左上角x和y坐标，再接下来2个参数是正方形的长和宽，然后是画弧的起始角度，最后一个参数是需要画多大的角度；