form1.vb

苏金明编写的《用VB.NET和VC#.NET开发交互式CAD系统》一书的源代码

Imports System.Drawing.Drawing2D

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。
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.BackColor = System.Drawing.Color.White
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Name = "Form1"
        Me.Text = "Form1"

    End Sub

#End Region


    Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
        Dim g As Graphics = e.Graphics
        '创建一个填充矩形
        Dim brush As New SolidBrush(Color.BlueViolet)
        g.FillRectangle(brush, 180, 70, 200, 150)
        '创建一个位图，其中的两个矩形之间有透明效果
        Dim bm1 As New Bitmap(200, 100)
        Dim bg1 As Graphics = Graphics.FromImage(bm1)
        Dim redBrush As New SolidBrush(Color.FromArgb(210, 255, 0, 0))
        Dim greenBrush As New SolidBrush(Color.FromArgb(210, 0, 255, 0))
        bg1.FillRectangle(redBrush, 0, 0, 150, 70)
        bg1.FillRectangle(greenBrush, 30, 30, 150, 70)
        g.DrawImage(bm1, 100, 100)
        '创建第二个位图，其中两个矩形之间没有透明效果
        Dim bm2 As New Bitmap(200, 100)
        Dim bg2 As Graphics = Graphics.FromImage(bm2)
        bg2.CompositingMode = CompositingMode.SourceCopy
        bg2.FillRectangle(redBrush, 0, 0, 150, 70)
        bg2.FillRectangle(greenBrush, 30, 30, 150, 70)
        g.CompositingQuality = CompositingQuality.GammaCorrected
        g.DrawImage(bm2, 300, 100)

    End Sub
End Class