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.ClientSize = New System.Drawing.Size(292, 266)
        Me.Name = "Form1"
        Me.Text = "Form1"

    End Sub

#End Region



    Protected Overrides Sub OnPaint(ByVal e As Windows.Forms.PaintEventArgs)
        Dim g As Graphics = e.Graphics()
        g.FillRectangle(Brushes.White, Me.ClientRectangle)
        g.DrawLine(Pens.Black, New PointF(10, 10), New PointF(100, 100))
        g.DrawEllipse(Pens.Black, 150, 100, 100, 100)
        g.DrawArc(Pens.Black, 10, 80, 100, 100, 20, 80)
        Dim s As String = "拾取图元"
        Dim f As Font = New Font("宋体", 20)
        g.DrawString(s, f, Brushes.Black, 120, 50)

    End Sub

    Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As MouseEventArgs) Handles MyBase.MouseMove
        Dim aPos As New PointF(e.X, e.Y)
        Dim g As Graphics = CreateGraphics()
        Dim gp1 As New GraphicsPath()
        Dim gp2 As New GraphicsPath()
        Dim gp3 As New GraphicsPath()
        Dim gp4 As New GraphicsPath()
        gp1.AddLine(New PointF(10, 10), New PointF(100, 100))
        gp2.AddEllipse(150, 100, 100, 100)
        gp3.AddArc(10, 80, 100, 100, 20, 80)
        Dim s As String = "拾取图元"
        Dim sf As StringFormat = New StringFormat(StringFormatFlags.NoWrap)
        Dim f As FontFamily = New FontFamily("宋体")
        gp4.AddString(s, f, 0, 25, New PointF(120, 50), sf)
        Dim p1 As New Pen(Color.Black)
        Dim p2 As New Pen(Color.Red)
        Dim p3 As New Pen(Color.White)
        p2.DashStyle = DashStyle.Dash

        If gp1.IsOutlineVisible(aPos, Pens.Black) Then
            g.DrawPath(p3, gp1)
            g.DrawPath(p2, gp1)
        Else
            g.DrawPath(p1, gp1)
        End If
        If gp2.IsOutlineVisible(aPos, Pens.Black) Then
            g.DrawPath(p3, gp2)
            g.DrawPath(p2, gp2)
        Else
            g.DrawPath(p1, gp2)
        End If
        If gp3.IsOutlineVisible(aPos, Pens.Black) Then
            g.DrawPath(p3, gp3)
            g.DrawPath(p2, gp3)
        Else
            g.DrawPath(p1, gp3)
        End If
        If gp4.IsOutlineVisible(aPos, Pens.Black) Then
            g.DrawPath(p3, gp4)
            g.DrawPath(p2, gp4)
        Else
            g.DrawPath(p1, gp4)
        End If

        gp1.Dispose()
        gp2.Dispose()
        gp3.Dispose()
        gp4.Dispose()
        p1.Dispose()
        p2.Dispose()

    End Sub


End Class