WPF 极坐标简单应用

WPF 极坐标简单应用

在圆形布局中说过极坐标。

极坐标是长度和边与极轴之间的角度的坐标表示。

换句话说，只要知道角度和长度（与中心点的距离），我们就能求出这一点的坐标，相对的我们知道这个一点的XY坐标也能求出角度和长度。

极坐标的工具性真的很强，在绘图，动画上 有很大的帮助，计算过程要简单不少。

下面我给出一个简单的小栗子

截图：

 

using System;using System.Windows;using System.Windows.Input;using System.Windows.Media;using System.Windows.Shapes;namespace 极坐标综合应用{ /// <summary> /// MainWindow.xaml 的交互逻辑 /// </summary> public partial class MainWindow : Window {  public MainWindow()  {   InitializeComponent();  }  private Line DrawLine;  private bool IsDraw;   private Line SetBaseLine() => new Line() {Stroke=new SolidColorBrush(Colors.Red),StrokeThickness=1.1 };  private void C1_MouseDown(object sender, MouseButtonEventArgs e)  {   if(e.LeftButton==MouseButtonState.Pressed)   {    c1.Children.Clear();    IsDraw = true;        DrawLine = SetBaseLine();    DrawLine.X1 = e.GetPosition(c1).X;    DrawLine.Y1 = e.GetPosition(c1).Y;    DrawLine.X2 = e.GetPosition(c1).X;    DrawLine.Y2 = e.GetPosition(c1).Y;    c1.Children.Add(DrawLine);   }  }  private void C1_MouseMove(object sender, MouseEventArgs e)  {   if(e.LeftButton==MouseButtonState.Pressed)   if(IsDraw==true)   {    DrawLine.X2 = e.GetPosition(c1).X;    DrawLine.Y2 = e.GetPosition(c1).Y;   }  }  private void C1_MouseUp(object sender, MouseButtonEventArgs e)  {   if (e.LeftButton == MouseButtonState.Released)   {    IsDraw = false;    CoodSystem();   }  }  private void CoodSystem()  {   var startpoint = new Point(DrawLine.X1, DrawLine.Y1);   var enpoint = new Point(DrawLine.X2, DrawLine.Y2);   //转换为笛卡尔坐标   var sub = Point.Subtract(enpoint, startpoint);   var x = sub.X;   var y = sub.Y;   //转换公式   sub = new Vector(x, 0 - y);   //求出tan   var k = y / x;   //转换角度   var angle = 180 / Math.PI * Math.Atan2(y, x);   t1.Text = $"{(angle<=0?Math.Abs(angle):360-angle)}度";  }  double ToRandion(double angle) => angle * (Math.PI / 180);  void Create(Line l1, double angle,double len)  {   //转极坐标公式求X值   var x = len * Math.Cos(ToRandion(angle));   //转极坐标公式求Y值   var y = len * Math.Sin(ToRandion(angle));   //笛卡尔转屏幕坐标   x =l1.X1 + x;   y = l1.Y1 - y;   l1.X2 = x;   l1.Y2 = y;  }  Point GetMid() => new Point(c1.ActualWidth / 2, c1.ActualHeight / 2);  private void T2_KeyDown(object sender, KeyEventArgs e)  {   var x =Convert.ToDouble( xt.Text);   var y = Convert.ToDouble(yt.Text);   var len = Convert.ToDouble(lt.Text);   c1.Children.Clear();   DrawLine = SetBaseLine();   DrawLine.X1 = x;   DrawLine.Y1 = y;   Create(DrawLine, Convert.ToDouble(t2.Text),len);   c1.Children.Add(DrawLine);  } }}