form1.vb

这是一本用Visual Studio.NET进行多媒体编程的读物

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

    '窗体重写处置以清理组件列表。
    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
    <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.SuspendLayout()
        '
        'PictureBox1
        '
        Me.PictureBox1.BackColor = System.Drawing.SystemColors.ActiveCaptionText
        Me.PictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
        Me.PictureBox1.Location = New System.Drawing.Point(8, 8)
        Me.PictureBox1.Name = "PictureBox1"
        Me.PictureBox1.Size = New System.Drawing.Size(272, 288)
        Me.PictureBox1.TabIndex = 0
        Me.PictureBox1.TabStop = False
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(288, 16)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(104, 32)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "加载图象"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(288, 64)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(104, 32)
        Me.Button2.TabIndex = 2
        Me.Button2.Text = "清除图象"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(288, 112)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(104, 32)
        Me.Button3.TabIndex = 3
        Me.Button3.Text = "绘制多边形图形"
        '
        'Button4
        '
        Me.Button4.Location = New System.Drawing.Point(288, 160)
        Me.Button4.Name = "Button4"
        Me.Button4.Size = New System.Drawing.Size(104, 32)
        Me.Button4.TabIndex = 4
        Me.Button4.Text = "清除图片框内容"
        '
        'Button5
        '
        Me.Button5.Location = New System.Drawing.Point(288, 208)
        Me.Button5.Name = "Button5"
        Me.Button5.Size = New System.Drawing.Size(104, 32)
        Me.Button5.TabIndex = 5
        Me.Button5.Text = "绘制图象"
        '
        'Button6
        '
        Me.Button6.Location = New System.Drawing.Point(288, 256)
        Me.Button6.Name = "Button6"
        Me.Button6.Size = New System.Drawing.Size(104, 40)
        Me.Button6.TabIndex = 6
        Me.Button6.Text = "按指定区域绘制图象"
        '
        'Button7
        '
        Me.Button7.Location = New System.Drawing.Point(160, 312)
        Me.Button7.Name = "Button7"
        Me.Button7.Size = New System.Drawing.Size(112, 40)
        Me.Button7.TabIndex = 7
        Me.Button7.Text = "获取象素颜色并填充矩形"
        '
        'Button8
        '
        Me.Button8.Location = New System.Drawing.Point(288, 312)
        Me.Button8.Name = "Button8"
        Me.Button8.Size = New System.Drawing.Size(104, 40)
        Me.Button8.TabIndex = 8
        Me.Button8.Text = "改变象素的颜色"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(424, 359)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Button8, Me.Button7, Me.Button6, Me.Button5, Me.Button4, Me.Button3, Me.Button2, Me.Button1, Me.PictureBox1})
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Dim g As Graphics
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' 设置一个有效的图片文件名称。
        Dim path As String = "c:\myBitmap.bmp"
        ' 使用 Image 类的 FromFile 方法设置PictureBox控件的Image 属性
        PictureBox1.Image = Image.FromFile(path)
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        PictureBox1.Image = Nothing
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        'Dim g As Graphics = Button1.CreateGraphics
        Dim myBrush As New SolidBrush(Color.Red)
        g.FillPie(myBrush, New Rectangle(110, 110, 300, 300), 0, 90)  '填充扇形区的内部。

        Dim myPen As New Pen(Color.Red)
        myPen.Width = 5
        g.DrawLine(myPen, 1, 1, 45, 65)
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        'g.Clear(Color.White)
        'Dim g As Graphics = PictureBox1.CreateGraphics

        'g.Graphics.Clear(Color.Teal)
        g.Clear(Color.Teal)

    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        g = PictureBox1.CreateGraphics
    End Sub

    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
        'Create image.
        Dim newImage As Image = Image.FromFile("c:\SampImag.jpg")
        ' Create Point for upper-left corner of image.
        Dim ulCorner As New Point(10, 10)
        ' Draw image to picturebox1.
        g.DrawImage(newImage, ulCorner)
        'e.Graphics.DrawImage(newImage, ulCorner)

    End Sub

    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
        '从示例文件夹中的JPEG文件SampImag.jpg创建图像
        Dim newImage As Image = Image.FromFile("c:\SampImag.jpg")
        '创建定义平行四边形的点，要在该平行四边形中绘制图像
        Dim ulCorner As New Point(10, 10)
        Dim urCorner As New Point(350, 150)
        Dim llCorner As New Point(150, 250)
        Dim destPara As Point() = {ulCorner, urCorner, llCorner}
        '将图像绘制到PictureBox1
        g.DrawImage(newImage, destPara)
    End Sub

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        '从示例文件夹中的Grapes.jpg文件创建myBitmap对象
        Dim myBitmap As New Bitmap("c:\SampImag.jpg")
        '从myBitmap 对象中获取指定象素的颜色值
        Dim pixelColor As Color = myBitmap.GetPixel(100, 100)
        '用pixelColor填充一个矩形区域
        Dim pixelBrush As New SolidBrush(pixelColor)
        g.FillRectangle(pixelBrush, 100, 100, 200, 200)
    End Sub

    Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click
        '从示例文件夹中的Grapes.jpg文件创建myBitmap对象
        Dim myBitmap As New Bitmap("c:\SampImag.jpg")
        '将myBitmap绘制到PictureBox1
        g.DrawImage(myBitmap, 0, 0, myBitmap.Width, myBitmap.Height)
        '将MyBitmap对象的每一点都设置为黑色
        Dim Xcount As Integer
        For Xcount = 0 To myBitmap.Width - 1
            Dim Ycount As Integer
            For Ycount = 0 To myBitmap.Height - 1
                myBitmap.SetPixel(Xcount, Ycount, Color.Black)
            Next Ycount
        Next Xcount
        '再次将myBitmap绘制到PictureBox1
        g.DrawImage(myBitmap, 0, 0, myBitmap.Width, myBitmap.Height)
    End Sub

End Class