常用不常用，要看每个人的编程方向和使用习惯的！一般字符串函数和类型转换函数都是要用的
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Dim b As New Bitmap(PictureBox1.Width, PictureBox1.Height)
Dim g As Graphics = Graphics.FromImage(b)
g.Clear(Color.White)
Dim p As New Pen(Color.Black)
p.EndCap = Drawing2D.LineCap.ArrowAnchor
g.DrawLine(p, 30, PictureBox1.Height - 30, 30, 30)
g.DrawLine(p, 30, PictureBox1.Height - 30, PictureBox1.Width - 30, PictureBox1.Height - 30)
Dim i As Integer
Dim bs As New SolidBrush(Color.Green)
Dim po As New Point
po.X = 0
po.Y = PictureBox1.Height - 35
For i = 700 To 1000 Step 50
g.DrawString(i, Me.Font, bs, po.X, po.Y)
g.DrawLine(p, po.X + 28, po.Y + 5, po.X + 30, po.Y + 5)
po.Y -= (PictureBox1.Height - 100) / 6
Next
po.X = 30
po.Y = PictureBox1.Height - 30
For i = 0 To 40 Step 5
g.DrawString(i, Me.Font, bs, po.X, po.Y + 5)
g.DrawLine(p, po.X, po.Y + 2, po.X, po.Y)
po.X += (PictureBox1.Width - 100) / 8
Next
PictureBox1.Image = b
VB系统的坐标原点在左上角，X轴的正方向是水平向右，而Y轴的正方向是垂直向下。所以，要绘制三角函数的曲线，自己可以通过改变点坐标的方法来实现，当然，VB.NET提供了相应的方法可以来实现坐标变换，也可以通过VB.Net的Graphics类提供的平移、旋转等转换来实现。
下面是我通过自己变换实现的示例，提供参考；我的环境是VB.NET 2010
Imports System.Math
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'1，获得一个Graphics对象
Dim MyGraphics As Graphics
MyGraphics = PictureBox1.CreateGraphics
'2，定义一个Pen对象，用于绘制图形（轮廓线）
Dim MyPen As New Pen(Color.Black, 1)
'3，定义一个Brush对象，用于填充图形（如果需要填充的话）
Dim MyBrush As New SolidBrush(Color.Orange)
MyGraphics.DrawLine(MyPen, 0, 200, 700, 200)
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
'1，获得一个Graphics对象
Dim MyGraphics As Graphics
MyGraphics = PictureBox1.CreateGraphics
'2，定义一个Pen对象，用于绘制图形（轮廓线）
Dim MyPen As New Pen(Color.Black, 1)
'3，定义一个Brush对象，用于填充图形（如果需要填充的话）
Dim MyBrush As New SolidBrush(Color.Orange)
'声明横向和纵向比例变量
Dim Heng As Integer = 20
Dim Zong As Integer = 50
'先获得正弦值，保存到点坐标数组
Dim MyPoints(700) As Point
Dim i As Integer
For i = 0 To 700
MyPoints(i) = New Point(i * Heng, 200 + Sin(i) * Zong)
Next
'采用绘制光滑线连接点的方式绘制曲线
MyGraphics.DrawCurve(MyPen, MyPoints)
End Sub
End Class
显示的效果图：
