Programming Microsoft Visual Basic .NET/Programming Microsoft Visual Basic .NET (Microsoft Press)(X08-78517)(2002).bin/18 gdiplus/gdidemo/graphicprimitives.vb

Text File | 2002-02-06 | 14.2 KB | 398 lines

Imports System.Drawing.Drawing2D

Public Class DrawingPrimitives
    Inherits System.Windows.Forms.Form

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    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
    Friend WithEvents MainMenu1 As System.Windows.Forms.MainMenu
    Friend WithEvents MenuItem1 As System.Windows.Forms.MenuItem
    Friend WithEvents mnuPaint As System.Windows.Forms.MenuItem
    Friend WithEvents mnuResize As System.Windows.Forms.MenuItem
    Friend WithEvents mnuLines As System.Windows.Forms.MenuItem
    Friend WithEvents MenuItem9 As System.Windows.Forms.MenuItem
    Friend WithEvents mnuPolygons As System.Windows.Forms.MenuItem
    Friend WithEvents mnuCardinal As System.Windows.Forms.MenuItem
    Friend WithEvents mnuBezier As System.Windows.Forms.MenuItem
    Friend WithEvents mnuPens As System.Windows.Forms.MenuItem
    Friend WithEvents mnuPenAlignment As System.Windows.Forms.MenuItem
    Friend WithEvents mnuDashedLines As System.Windows.Forms.MenuItem
    Friend WithEvents mnuPaths As System.Windows.Forms.MenuItem

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.Container

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.
    'Do not modify it using the code editor.
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.mnuPaint = New System.Windows.Forms.MenuItem()
        Me.mnuResize = New System.Windows.Forms.MenuItem()
        Me.mnuPenAlignment = New System.Windows.Forms.MenuItem()
        Me.mnuPolygons = New System.Windows.Forms.MenuItem()
        Me.MainMenu1 = New System.Windows.Forms.MainMenu()
        Me.MenuItem1 = New System.Windows.Forms.MenuItem()
        Me.MenuItem9 = New System.Windows.Forms.MenuItem()
        Me.mnuLines = New System.Windows.Forms.MenuItem()
        Me.mnuCardinal = New System.Windows.Forms.MenuItem()
        Me.mnuBezier = New System.Windows.Forms.MenuItem()
        Me.mnuPens = New System.Windows.Forms.MenuItem()
        Me.mnuDashedLines = New System.Windows.Forms.MenuItem()
        Me.mnuPaths = New System.Windows.Forms.MenuItem()
        '
        'mnuPaint
        '
        Me.mnuPaint.Index = 0
        Me.mnuPaint.Text = "Draw an ellipse in Paint event"
        '
        'mnuResize
        '
        Me.mnuResize.Index = 1
        Me.mnuResize.Text = "Draw an ellipse in Resize event"
        '
        'mnuPenAlignment
        '
        Me.mnuPenAlignment.Index = 8
        Me.mnuPenAlignment.Text = "Pen Alignments"
        '
        'mnuPolygons
        '
        Me.mnuPolygons.Index = 4
        Me.mnuPolygons.Text = "Multiple Lines and Polygons"
        '
        'MainMenu1
        '
        Me.MainMenu1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.MenuItem1})
        '
        'MenuItem1
        '
        Me.MenuItem1.Index = 0
        Me.MenuItem1.MenuItems.AddRange(New System.Windows.Forms.MenuItem() {Me.mnuPaint, Me.mnuResize, Me.MenuItem9, Me.mnuLines, Me.mnuPolygons, Me.mnuCardinal, Me.mnuBezier, Me.mnuPens, Me.mnuPenAlignment, Me.mnuDashedLines, Me.mnuPaths})
        Me.MenuItem1.Text = "Examples"
        '
        'MenuItem9
        '
        Me.MenuItem9.Index = 2
        Me.MenuItem9.Text = "-"
        '
        'mnuLines
        '
        Me.mnuLines.Index = 3
        Me.mnuLines.Text = "Line, Rectangle, Ellipse"
        '
        'mnuCardinal
        '
        Me.mnuCardinal.Index = 5
        Me.mnuCardinal.Text = "Cardinal splines"
        '
        'mnuBezier
        '
        Me.mnuBezier.Index = 6
        Me.mnuBezier.Text = "Bezier splines"
        '
        'mnuPens
        '
        Me.mnuPens.Index = 7
        Me.mnuPens.Text = "Pens"
        '
        'mnuDashedLines
        '
        Me.mnuDashedLines.Index = 9
        Me.mnuDashedLines.Text = "Dashed lines and arrow caps"
        '
        'mnuPaths
        '
        Me.mnuPaths.Index = 10
        Me.mnuPaths.Text = "Paths"
        '
        'DrawingPrimitives
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(7, 17)
        Me.ClientSize = New System.Drawing.Size(576, 341)
        Me.Font = New System.Drawing.Font("Microsoft Sans Serif", 11!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Menu = Me.MainMenu1
        Me.Name = "DrawingPrimitives"
        Me.Text = "Drawing primitives"

    End Sub

#End Region

    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        If mnuPaint.Checked = False Then Exit Sub

        ' Get the Graphics object corresponding to the form's surface.
        Dim gr As Graphics = e.Graphics
        ' Clear the background.
        gr.Clear(Color.Azure)
        ' Draw an ellipse as large as the form.
        gr.DrawEllipse(Pens.Red, 0, 0, Me.ClientSize.Width, Me.ClientSize.Height)
    End Sub


    Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Resize
        If mnuResize.Checked = False Then Exit Sub

        ' Get the Graphics object corresponding to the form's surface.
        Dim gr As Graphics = Me.CreateGraphics
        ' Clear the background.
        gr.Clear(Color.Azure)
        ' Draw an ellipse as large as the form.
        gr.DrawEllipse(Pens.Red, 0, 0, Me.ClientSize.Width, Me.ClientSize.Height)
        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuPaint_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuPaint.Click, mnuResize.Click
        With CType(sender, MenuItem)
            .Checked = Not .Checked
        End With
        ' Force a refresh.
        Me.Invalidate()
    End Sub

    Private Sub mnuLines_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuLines.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        ' Draw a red line from (100, 30) to (500, 300).
        gr.DrawLine(Pens.Red, 100, 30, 500, 300)
        ' Draw a white square with left-top corner at (130, 50) and side=300 pixels.
        gr.DrawRectangle(Pens.White, New Rectangle(130, 50, 300, 300))
        ' Draw a green circle with radius=200 and center at (350,250)
        Dim r As Integer = 200
        gr.DrawEllipse(Pens.Green, 350 - r, 250 - r, r * 2, r * 2)

        Dim r2 As Integer = 100
        gr.DrawArc(Pens.Blue, 200 - r2, 150 - r2, r2 * 2, r2 * 2, 0, 90)

        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuPolygons_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuPolygons.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics

        ' Draw three straight lines.
        Dim points() As Point = {New Point(10, 10), New Point(100, 80), New Point(200, 20), New Point(300, 100)}
        gr.DrawLines(Pens.Black, points)

        ' Draw a rhomb.
        gr.DrawPolygon(Pens.Red, New Point() {New Point(200, 50), New Point(300, 100), New Point(200, 150), New Point(100, 100)})

        ' Draw three rectangles.
        Dim rects() As Rectangle = {New Rectangle(50, 30, 200, 100), New Rectangle(70, 40, 220, 110), New Rectangle(90, 50, 240, 120)}
        gr.DrawRectangles(Pens.Green, rects)

        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuCardinal_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuCardinal.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        gr.Clear(Color.White)

        Dim points() As Point = {New Point(100, 100), New Point(200, 200), New Point(250, 30), New Point(350, 100)}
        Dim tension As Single

        For tension = 0 To 2 Step 0.5
            gr.DrawCurve(Pens.Black, points, tension)
        Next

        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuBezier_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuBezier.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        gr.Clear(Color.White)

        gr.DrawBezier(Pens.Black, New Point(10, 30), New Point(100, 20), New Point(140, 190), New Point(200, 200))
        gr.DrawLine(Pens.Red, New Point(10, 30), New Point(100, 20))
        gr.DrawLine(Pens.Red, New Point(200, 200), New Point(140, 190))


        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuPens_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuPens.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        gr.Clear(Color.White)

        ' Draw the inner rectanble with a pen of custom color.
        Dim p1 As New Pen(Color.FromArgb(128, 0, 60))
        gr.DrawRectangle(p1, 50, 50, 100, 50)
        ' Draw the outer rectangle with a blue pen 4 pixel wide.
        Dim p2 As New Pen(Color.Blue, 4)
        gr.DrawRectangle(p2, 10, 10, 200, 100)

        ' Destroy the Pen objects
        p1.Dispose()
        p2.Dispose()

        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuPenAlignment_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuPenAlignment.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        gr.Clear(Color.White)

        Dim p As New Pen(Color.Yellow, 12)
        Dim rect As New Rectangle(20, 20, 100, 100)

        gr.DrawRectangle(p, rect)
        gr.DrawRectangle(Pens.Black, rect)

        p.Alignment = Drawing.Drawing2D.PenAlignment.Inset
        rect.Offset(150, 0)
        gr.DrawRectangle(p, rect)
        gr.DrawRectangle(Pens.Black, rect)
        p.Dispose()

        ' Enable this block of code to show that other alignment settings have no effect
#If 0 Then
        p = New Pen(Color.Red, 12)
        p.Alignment = Drawing.Drawing2D.PenAlignment.Left
        gr.DrawLine(p, 20, 180, 200, 180)
        gr.DrawLine(Pens.Black, 20, 180, 200, 180)
        p.Dispose()


        p = New Pen(Color.Yellow, 12)
        p.Alignment = Drawing.Drawing2D.PenAlignment.Right
        gr.DrawLine(p, 20, 220, 200, 220)
        gr.DrawLine(Pens.Black, 20, 220, 200, 220)
        p.Dispose()
#End If

        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub

    Private Sub mnuDashedLines_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuDashedLines.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        gr.Clear(Color.White)

        ' a custom pen
        Dim p As New Pen(Color.Black, 3)
        p.DashStyle = Drawing.Drawing2D.DashStyle.Dash
        gr.DrawLine(p, 10, 10, 200, 10)
        p.DashStyle = Drawing.Drawing2D.DashStyle.DashDot
        gr.DrawLine(p, 10, 30, 200, 30)
        p.DashStyle = Drawing.Drawing2D.DashStyle.DashDotDot
        gr.DrawLine(p, 10, 50, 200, 50)
        p.DashStyle = Drawing.Drawing2D.DashStyle.Dot
        gr.DrawLine(p, 10, 70, 200, 70)

        ' create a custom dash pattern.
        Dim sngArray() As Single = {4, 4, 8, 4, 12, 4}
        p.DashPattern = sngArray
        gr.DrawLine(p, 10, 90, 200, 90)

        ' display pens with cap
        Dim p2 As New Pen(Color.Black, 8)
        p2.StartCap = Drawing.Drawing2D.LineCap.DiamondAnchor
        p2.EndCap = Drawing.Drawing2D.LineCap.ArrowAnchor
        gr.DrawLine(p2, 280, 30, 500, 30)

        p2.StartCap = Drawing.Drawing2D.LineCap.RoundAnchor
        p2.EndCap = Drawing.Drawing2D.LineCap.Round
        gr.DrawLine(p2, 280, 70, 500, 70)


        ' Destroy the Pen object.
        p.Dispose()
        p2.Dispose()
        ' Destroy the Graphics object.
        gr.Dispose()

    End Sub

    Private Sub mnuPaths_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles mnuPaths.Click
        ' Wait until the menu closes.
        Threading.Thread.Sleep(400)

        ' Create a Graphics object.
        Dim gr As Graphics = Me.CreateGraphics
        gr.Clear(Color.White)

        ' Create a new Path object.
        Dim pa As New GraphicsPath()
        ' Start a figure.
        pa.StartFigure()
        pa.AddRectangle(New Rectangle(20, 20, 200, 150))
        pa.AddRectangle(New Rectangle(50, 50, 200, 150))
        pa.AddLine(20, 20, 50, 50)
        pa.StartFigure()   ' Avoid connecting the two segments.
        pa.AddLine(220, 20, 250, 50)
        pa.StartFigure()   ' Avoid connecting the two segments.
        pa.AddLine(220, 170, 250, 200)
        pa.StartFigure()   ' Avoid connecting the two segments.
        pa.AddLine(20, 170, 50, 200)

        ' Start another (closed) figure.
        pa.StartFigure()
        pa.AddLine(300, 20, 400, 20)
        pa.AddLine(400, 20, 400, 120)
        pa.CloseFigure()

        ' Draw the path, using a thick red pen
        Dim p As New Pen(Color.Red, 3)
        gr.DrawPath(p, pa)

        pa.Dispose()
        p.Dispose()


        ' Destroy the Graphics object.
        gr.Dispose()
    End Sub
End Class