最近專案要用C#實現畫一個雷達圖，搜了搜網上竟然找不到C#畫雷達圖的解決方案，那麼自己實現一個吧

實現效果如下圖：

程式碼如下：

public static class RadarDemo
  {
    static float mW = 1200;
    static float mH = 1200;
    static Dictionary<string,float> mData = new Dictionary<string,float>
    {
        //{ "速度",77},{ "力量",72},{ "防守",110},{ "射門",50},{ "傳球",80},{ "耐力",60 }
    };//維度資料
    static float mCount = mData.Count; //邊數
    static float mCenter = mW * 0.5f; //中心點
    static float mRadius = mCenter - 100; //半徑(減去的值用於給繪製的文字留空間)
    static double mAngle = (Math.PI * 2) / mCount; //角度
    static Graphics graphics = null;
    static int mPointRadius = 5; // 各個維度分值圓點的半徑  
    static int textFontSize = 18;  //頂點文字大小 px
    const string textFontFamily = "Microsoft Yahei"; //頂點字型
    static Color lineColor = Color.Green;
    static Color fillColor = Color.FromArgb(128,255,0);
    static Color fontColor = Color.Black;
    public static void Show()
    {
      Bitmap img = new Bitmap((int)mW,(int)mH); 
      graphics = Graphics.FromImage(img); 
      graphics.Clear(Color.White);
      img.Save($"{AppDomain.CurrentDomain.BaseDirectory}radar/0.png",ImageFormat.Png);
      DrawPolygon(graphics);
      img.Save($"{AppDomain.CurrentDomain.BaseDirectory}radar/1.png",ImageFormat.Png);
      DrawLines(graphics);
      img.Save($"{AppDomain.CurrentDomain.BaseDirectory}radar/2.png",ImageFormat.Png);
      DrawText(graphics);
      img.Save($"{AppDomain.CurrentDomain.BaseDirectory}radar/3.png",ImageFormat.Png);
      DrawRegion(graphics);
      img.Save($"{AppDomain.CurrentDomain.BaseDirectory}radar/4.png",ImageFormat.Png);
      DrawCircle(graphics);
      img.Save($"{AppDomain.CurrentDomain.BaseDirectory}radar/5.png",ImageFormat.Png);
      img.Dispose();
      graphics.Dispose();
    }
    // 繪製多邊形邊
    private static void DrawPolygon(Graphics ctx)
    {
      var r = mRadius / mCount; //單位半徑
      Pen pen = new Pen(lineColor);
      //畫6個圈
      for (var i = 0; i < mCount; i++)
      {
        var points = new List<PointF>();
        var currR = r * (i + 1); //當前半徑
        //畫6條邊
        for (var j = 0; j < mCount; j++)
        {
          var x = (float)(mCenter + currR * Math.Cos(mAngle * j));
          var y = (float)(mCenter + currR * Math.Sin(mAngle * j));
          points.Add(new PointF { X = x,Y = y });
        }
        ctx.DrawPolygon(pen,points.ToArray());
        //break;
      }
      ctx.Save();
    }
    //頂點連線
    private static void DrawLines(Graphics ctx)
    {
      for (var i = 0; i < mCount; i++)
      {
        var x = (float)(mCenter + mRadius * Math.Cos(mAngle * i));
        var y = (float)(mCenter + mRadius * Math.Sin(mAngle * i));
        ctx.DrawLine(new Pen(lineColor),new PointF { X = mCenter,Y = mCenter },new PointF { X = x,Y = y });
        //break;
      }
      ctx.Save();
    }
    //繪製文字
    private static void DrawText(Graphics ctx)
    {
      var fontSize = textFontSize;//mCenter / 12;
      Font font = new Font(textFontFamily,fontSize,FontStyle.Regular);
      int i = 0;
      foreach (var item in mData)
      {
        var x = (float)(mCenter + mRadius * Math.Cos(mAngle * i));
        var y = (float)(mCenter + mRadius * Math.Sin(mAngle * i) - fontSize);
        if (mAngle * i > 0 && mAngle * i <= Math.PI / 2)
        {
          ctx.DrawString(item.Key,font,new SolidBrush(fontColor),x - ctx.MeasureString(item.Key,font).Width * 0.5f,y + fontSize/* y + fontSize*/);
        }
        else if (mAngle * i > Math.PI / 2 && mAngle * i <= Math.PI)
        {
          ctx.DrawString(item.Key,font).Width,y /*y + fontSize*/);
        }
        else if (mAngle * i > Math.PI && mAngle * i <= Math.PI * 3 / 2)
        {
          ctx.DrawString(item.Key,y);
        }
        else if (mAngle * i > Math.PI * 3 / 2)
        {
          ctx.DrawString(item.Key,y - fontSize * 0.5f);
        }
        else
        {
          ctx.DrawString(item.Key,x,y /* y + fontSize*/);
        }
        i++;
      }
      ctx.Save();
    }
    //繪製資料區域
    private static void DrawRegion(Graphics ctx)
    {
      int i = 0;
      List<PointF> points = new List<PointF>();
      foreach (var item in mData)
      {
        var x = (float)(mCenter + mRadius * Math.Cos(mAngle * i) * item.Value / 100);
        var y = (float)(mCenter + mRadius * Math.Sin(mAngle * i) * item.Value / 100);
        points.Add(new PointF { X = x,Y = y });
        //ctx.DrawArc(new Pen(lineColor),y,r,(float)Math.PI * 2); 
        i++;
      }
      //GraphicsPath path = new GraphicsPath();
      //path.AddLines(points.ToArray());
      ctx.FillPolygon(new SolidBrush(fillColor),points.ToArray());
      ctx.Save();
    }
    //畫點
    private static void DrawCircle(Graphics ctx)
    {
      //var r = mCenter / 18;
      var r = mPointRadius;
      int i = 0;
      foreach (var item in mData)
      {
        var x = (float)(mCenter + mRadius * Math.Cos(mAngle * i) * item.Value / 100);
        var y = (float)(mCenter + mRadius * Math.Sin(mAngle * i) * item.Value / 100);
        ctx.FillPie(new SolidBrush(fillColor),x - r,y - r,r * 2,360);
        //ctx.DrawArc(new Pen(lineColor),(float)Math.PI * 2); 
        i++;
      }
      ctx.Save();
    }
  }

把這個類貼上到你的專案中，執行RadarDemo.Show();就會在你的根目錄裡生成雷達圖了，為了方便理解怎麼畫出來的，我把畫每一個步驟時的圖片都儲存下來了。可以自行執行檢視

總結

以上所述是小編給大家介紹的C# 使用GDI繪製雷達圖的例項，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回覆大家的。在此也非常感謝大家對我們網站的支援！
如果你覺得本文對你有幫助，歡迎轉載，煩請註明出處，謝謝！