Question

如何用VB2012写一个画线程序

Answer 1

在窗体上添加一个PictureBox1控件，两个按钮控件：
代码如下：
Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'绘制图形的三步曲
'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)

'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.FillEllipse(MyBrush, 200, 200, 100, 100) '绘制一个实心圆，该圆在：直线x=200，y=200，x=200+100，y=200+100所划的矩形区域内
MyGraphics.DrawEllipse(MyPen, 200, 200, 100, 100) '绘制一个空心圆，该圆在：直线x=200，y=200，x=200+100，y=200+100所划的矩形区域内

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, 3)

'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)

Dim MyPoints() As Point = {New Point(20, 50), New Point(200, 30), New Point(250, 60)}
MyGraphics.SmoothingMode = Drawing2D.SmoothingMode.HighQuality
'MyGraphics.DrawClosedCurve(MyPen, MyPoints) '绘制光滑的封闭曲线
'MyGraphics.DrawCurve(MyPen, MyPoints) '绘制光滑的曲线

'用直线连接连点，绘制折线
Dim i As Integer
For i = 0 To 1
MyGraphics.DrawLine(MyPen, MyPoints(i), MyPoints(i + 1))
Next
End Sub
End Class