Graphics用来绘图。
用draw来划线。vb.net没有画点的功能。
可以画直接、矩形、椭圆、Bezier、弧、饼(封闭的弧线)。
要注意的是:弧、饼用的是度数(不是弧度),且是顺时间转的角度。
Imports System.Drawing Imports System.Math Public Class Form1 Const pi As Double = 3.14159 '画点(用一个像素的矩形或两个像素的直接来模拟 Private Sub Button1_Click(sender As Object,e As EventArgs) Handles Button1.Click Dim gr As Graphics = PictureBox1.CreateGraphics Dim j As Int32 = 50 For i As Int32 = 10 To 150 gr.DrawLine(Pens.Red,i,j,i + 1,j + 1) j += 1 Next End Sub '用直线构成图 Private Sub Button2_Click(sender As Object,e As EventArgs) Handles Button2.Click PictureBox1.Refresh() '清除 Dim gr As Graphics = PictureBox1.CreateGraphics Dim x1,y1,x2,y2,d As Short '起点终点、基准距离 Dim b,c As Double '真实距离 d = 60 For a = 0 To 2 * pi Step pi / 360 b = d * (1 + 1 / 4 * Cos(12 * a)) c = b * (1 + Sin(4 * a)) x1 = 150 + Int(c * Cos(a)) '(150,180)中心点 y1 = 180 + Int(c * Sin(a)) x2 = 150 + Int(c * Cos(a + pi / 5)) y2 = 180 + Int(c * Sin(a + pi / 5)) gr.DrawLine(Pens.BlueViolet,x1,y2) Next End Sub '椭圆或圆 Private Sub Button3_Click(sender As Object,e As EventArgs) Handles Button3.Click PictureBox1.Refresh() Dim gr As Graphics = PictureBox1.CreateGraphics gr.DrawEllipse(Pens.Red,New Rectangle(0,100,80)) gr.DrawEllipse(Pens.Aqua,New Rectangle(120,120,80,80)) End Sub '椭圆弧 或圆弧 (是对上面椭圆的部分提取) '注意:开始和结束角度是以度为单位,且顺时针方向,下面是从30度到120度 Private Sub Button4_Click(sender As Object,e As EventArgs) Handles Button4.Click PictureBox1.Refresh() Dim gr As Graphics = PictureBox1.CreateGraphics gr.DrawArc(Pens.Red,New Rectangle(20,20,150,200),30,120) End Sub '封闭椭圆弧线,即饼图 '参数与arc同,只是成图时是封闭的 Private Sub Button5_Click(sender As Object,e As EventArgs) Handles Button5.Click PictureBox1.Refresh() Dim gr As Graphics = PictureBox1.CreateGraphics gr.DrawPie(Pens.Red,120) End Sub '贝赛尔曲线 Bezier '它由四个点:起点、两个中间点(控制)、终点 组成 Private Sub Button6_Click(sender As Object,e As EventArgs) Handles Button6.Click PictureBox1.Refresh() Dim gr As Graphics = PictureBox1.CreateGraphics gr.DrawBezier(Pens.Brown,10,140,40,240,200,270) gr.DrawRectangle(Pens.Red,New Rectangle(200,170)) End Sub '多边形--不规则形状 '由多个点来决定,多个点用Points()数组来表达 Private Sub Button7_Click(sender As Object,e As EventArgs) Handles Button7.Click PictureBox1.Refresh() Dim gr As Graphics = PictureBox1.CreateGraphics Dim p(2) As System.Drawing.Point p(0).X = 30 : p(0).Y = 30 p(1).X = 100 : p(1).Y = 100 p(2).X = 50 : p(2).Y = 250 gr.DrawPolygon(Pens.DarkGreen,p) End Sub End Class