form1.vb

Source code for VB.NET book - Chapter 4

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents PictureBox1 As System.Windows.Forms.PictureBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    Friend WithEvents Button4 As System.Windows.Forms.Button
    Friend WithEvents Button5 As System.Windows.Forms.Button
    Friend WithEvents Button6 As System.Windows.Forms.Button
    Friend WithEvents Button7 As System.Windows.Forms.Button
    Friend WithEvents Button8 As System.Windows.Forms.Button
    Friend WithEvents Button9 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.PictureBox1 = New System.Windows.Forms.PictureBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.Button4 = New System.Windows.Forms.Button
        Me.Button5 = New System.Windows.Forms.Button
        Me.Button6 = New System.Windows.Forms.Button
        Me.Button7 = New System.Windows.Forms.Button
        Me.Button8 = New System.Windows.Forms.Button
        Me.Button9 = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'PictureBox1
        '
        Me.PictureBox1.BackColor = System.Drawing.SystemColors.Window
        Me.PictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.PictureBox1.Dock = System.Windows.Forms.DockStyle.Left
        Me.PictureBox1.Location = New System.Drawing.Point(0, 0)
        Me.PictureBox1.Name = "PictureBox1"
        Me.PictureBox1.Size = New System.Drawing.Size(208, 266)
        Me.PictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.AutoSize
        Me.PictureBox1.TabIndex = 0
        Me.PictureBox1.TabStop = False
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(240, 8)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(56, 24)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "点"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(240, 48)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(56, 24)
        Me.Button2.TabIndex = 2
        Me.Button2.Text = "直  线"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(240, 88)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(56, 24)
        Me.Button3.TabIndex = 3
        Me.Button3.Text = "椭  圆"
        '
        'Button4
        '
        Me.Button4.Location = New System.Drawing.Point(240, 128)
        Me.Button4.Name = "Button4"
        Me.Button4.Size = New System.Drawing.Size(56, 24)
        Me.Button4.TabIndex = 4
        Me.Button4.Text = "弧  形"
        '
        'Button5
        '
        Me.Button5.Location = New System.Drawing.Point(240, 168)
        Me.Button5.Name = "Button5"
        Me.Button5.Size = New System.Drawing.Size(56, 24)
        Me.Button5.TabIndex = 5
        Me.Button5.Text = "扇  形"
        '
        'Button6
        '
        Me.Button6.Location = New System.Drawing.Point(240, 208)
        Me.Button6.Name = "Button6"
        Me.Button6.Size = New System.Drawing.Size(56, 24)
        Me.Button6.TabIndex = 6
        Me.Button6.Text = "矩  形"
        '
        'Button7
        '
        Me.Button7.Location = New System.Drawing.Point(312, 8)
        Me.Button7.Name = "Button7"
        Me.Button7.Size = New System.Drawing.Size(56, 24)
        Me.Button7.TabIndex = 7
        Me.Button7.Text = "三角形"
        '
        'Button8
        '
        Me.Button8.Location = New System.Drawing.Point(312, 48)
        Me.Button8.Name = "Button8"
        Me.Button8.Size = New System.Drawing.Size(56, 24)
        Me.Button8.TabIndex = 8
        Me.Button8.Text = "多边形"
        '
        'Button9
        '
        Me.Button9.Location = New System.Drawing.Point(312, 88)
        Me.Button9.Name = "Button9"
        Me.Button9.Size = New System.Drawing.Size(56, 24)
        Me.Button9.TabIndex = 9
        Me.Button9.Text = "贝塞尔"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(376, 246)
        Me.Controls.Add(Me.Button9)
        Me.Controls.Add(Me.Button8)
        Me.Controls.Add(Me.Button7)
        Me.Controls.Add(Me.Button6)
        Me.Controls.Add(Me.Button5)
        Me.Controls.Add(Me.Button4)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.PictureBox1)
        Me.Name = "Form1"
        Me.Text = "线图"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Dim g As System.Drawing.Graphics
    Dim pen1 As New System.Drawing.Pen(Color.Red, 3)
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        PictureBox1.Refresh()
        g = PictureBox1.CreateGraphics
        Dim point1 As System.Drawing.Point
        Dim point2 As System.Drawing.Point
        Dim i, x, y, bx, by, x0, y0, n, r As Short
        Const pi = 3.1415926
        Dim a As Single
        n = 3
        r = 20
        For x = 60 To 450 Step 60
            For y = 20 To 350 Step 60
                If n = 11 Then
                    n = 5
                Else
                    n = n + 2
                End If
                For a = 0 To 4 * pi Step 4 * pi / n
                    x0 = x + r * System.Math.Sin(a)
                    y0 = y - r * System.Math.Cos(a)
                    If a = 0 Then
                        point1.x = x0 : point1.y = y0 : bx = x0 : by = y0
                    Else
                        point2.X = x0 : point2.Y = y0
                        g.DrawLine(pen1, point1, point2)
                        point1 = point2
                    End If
                Next
                g.DrawLine(pen1, point1, point2)
            Next
        Next
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        g = PictureBox1.CreateGraphics
        g.DrawLine(pen1, 20, 20, 160, 160)
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        g = PictureBox1.CreateGraphics
        g.DrawEllipse(pen1, 50, 50, 100, 150)
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        g = PictureBox1.CreateGraphics
        g.DrawArc(pen1, 90, 50, 100, 150, 150, 160)
    End Sub

    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
        g = PictureBox1.CreateGraphics
        g.DrawPie(pen1, 50, 50, 150, 150, 0, 170)
    End Sub

    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
        g = PictureBox1.CreateGraphics
        g.DrawRectangle(pen1, 30, 30, 50, 60)
    End Sub

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        Dim p(3) As System.Drawing.Point
        p(0).X = 0
        p(0).Y = 0
        p(1).X = 40
        p(1).Y = 120
        p(2).X = 110
        p(2).Y = 70
        g = PictureBox1.CreateGraphics
        g.DrawPolygon(pen1, p)
    End Sub

    Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click
        Dim p(5) As System.Drawing.Point
        p(0).X = 0
        p(0).Y = 0
        p(1).X = 40
        p(1).Y = 120
        p(2).X = 110
        p(2).Y = 70
        p(3).X = 30
        p(3).Y = 30
        p(4).X = 170
        p(4).Y = 10
        g = PictureBox1.CreateGraphics
        g.DrawPolygon(pen1, p)
    End Sub

    Private Sub Button9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button9.Click
        g = PictureBox1.CreateGraphics
        g.DrawBezier(pen1, 10, 20, 140, 150, 100, 30, 150, 200)
    End Sub
End Class