Delphi实现正弦曲线的绘制varx: Integer;y,a: Double;beginCanvas.Pen.Width:=3;Canvas.MoveTo(0,Trunc(self.ClientHeight/2);for x := 0 to self.ClientWidth dobegina := (x/self.ClientWidth) * 2 * Pi;y := Sin(a);y := (1-y)*self.ClientHeight/2;Canvas.LineTo(Trunc(x), Trunc(y);end;end; 程序首先设置了窗体的Canvas对象中画笔的宽度，并且把绘图的起点移动到了窗体中(0,Trunc(self.ClientHeight/2)的位置。然后通过一个循环中的a:= (x/self.ClientWidth)*2*Pi语句将一个正弦周期内的角度值转换为弧度值，并且把正弦计算后的结果存储在变量y中。最终，循环中的Canvas.LineTo(Trunc(x), Trunc(y)语句就会在窗体上绘制出连续的正弦曲线。 程序代码如下： unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ExtCtrls, StdCtrls; type TForm1 = class(TForm)procedure FormPaint(Sender: TObject);procedure FormResize(Sender: TObject);procedure FormCreate(Sender: TObject);private Private declarations public Public declarations end; var Form1: TForm1;implementation$R *.dfmprocedure TForm1.FormPaint(Sender: TObject);varx: Integer;y,a: Double;beginCanvas.Pen.Width:=3;Canvas.MoveTo(0,Trunc(self.ClientHeight/2);for x := 0 to self.ClientWidth dobegina := (x/self.ClientWidth) * 2 * Pi;y := Sin(a);y := (1-y)*self.ClientHeight/2;Canvas.LineTo(Trunc(x), Trunc(y);end;end; procedure TForm1.FormResize(Sender: TObject); beginRefresh;end; procedure TForm1.FormCreate(Sender: TObject); beginself.DoubleBuffered:=true;/防止图形闪耀end;end.保存文件，然后按F9键运行程序。在程序运行过程中，会自动在窗体上绘制正弦曲线 通过本程序的学习，不但可以绘制正弦曲线，也可以绘制余弦曲线、正切曲线等各式各样的曲线，便利科学讨论。