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 Button2 As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    Friend WithEvents Button4 As System.Windows.Forms.Button
    Friend WithEvents Panel1 As System.Windows.Forms.Panel
    Friend WithEvents Panel2 As System.Windows.Forms.Panel
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.Button4 = New System.Windows.Forms.Button
        Me.Panel1 = New System.Windows.Forms.Panel
        Me.Panel2 = New System.Windows.Forms.Panel
        Me.SuspendLayout()
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(88, 232)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(64, 24)
        Me.Button2.TabIndex = 3
        Me.Button2.Text = "翻  转"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(216, 232)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(64, 24)
        Me.Button3.TabIndex = 4
        Me.Button3.Text = "镜  像"
        '
        'Button4
        '
        Me.Button4.Location = New System.Drawing.Point(328, 232)
        Me.Button4.Name = "Button4"
        Me.Button4.Size = New System.Drawing.Size(56, 24)
        Me.Button4.TabIndex = 5
        Me.Button4.Text = "退  出"
        '
        'Panel1
        '
        Me.Panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.Panel1.Location = New System.Drawing.Point(24, 16)
        Me.Panel1.Name = "Panel1"
        Me.Panel1.Size = New System.Drawing.Size(200, 184)
        Me.Panel1.TabIndex = 10
        '
        'Panel2
        '
        Me.Panel2.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.Panel2.Location = New System.Drawing.Point(248, 16)
        Me.Panel2.Name = "Panel2"
        Me.Panel2.Size = New System.Drawing.Size(208, 184)
        Me.Panel2.TabIndex = 11
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(464, 286)
        Me.Controls.Add(Me.Panel2)
        Me.Controls.Add(Me.Panel1)
        Me.Controls.Add(Me.Button4)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Dim pic1, pic2 As Bitmap
    Dim flag As Integer = 0


    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        flag = 1
        Panel2.Invalidate()
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        flag = 2
        Panel2.Invalidate()
    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Panel1.Height = Panel1.Width
        Panel2.Width = Panel1.Width
        Panel2.Height = Panel2.Width
        Dim pic As Image = Image.FromFile("Water lilies.jpg")
        pic1 = New Bitmap(pic, Panel1.Width, Panel1.Height)
        pic2 = New Bitmap(pic1)
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        End
    End Sub

    Private Sub Panel1_Paint1(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint
        Dim g As Graphics = e.Graphics
        g.DrawImage(pic1, 0, 0)
    End Sub

    Private Sub Panel2_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel2.Paint
        Dim g As Graphics = e.Graphics
        Dim x As Integer = Panel2.Width
        Dim col As Color = New Color
        Select Case flag
            Case 1
                Dim pic3 As Bitmap
                pic3 = New Bitmap(x, x)
                Dim i, j As Integer
                For i = 0 To x - 1
                    For j = 0 To x - 1
                        col = pic2.GetPixel(i, j)
                        pic3.SetPixel(i, x - 1 - j, col)
                    Next
                Next
                g.DrawImage(pic3, 0, 0)
                pic2 = New Bitmap(pic3)
            Case 2
                Dim pic4 As Bitmap
                pic4 = New Bitmap(x, x)
                Dim i, j As Integer
                For i = 0 To x - 1
                    For j = 0 To x - 1
                        col = pic2.GetPixel(i, j)
                        pic4.SetPixel(x - i - 1, j, col)
                    Next
                Next
                g.DrawImage(pic4, 0, 0)
                pic2 = New Bitmap(pic4)
        End Select
        flag = 0
    End Sub
End Class