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Visual Basic 2008 Graphics - Drawing multiple circumscribed circles Part 2

Posted on 2009-05-07
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Last Modified: 2013-11-27
Circle within a circle within a circle...etc...etc...down to 1 point

Ellipses must have a constant radius on both x and y axis "Perfect Circles Only".

Please Include complete project (which includes form1) with screenshot.

CircleDemo2.jpg
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Question by:NerdsOfTech
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7 Comments
 
LVL 86

Accepted Solution

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Mike Tomlinson earned 500 total points
ID: 24331342
Same thing but going inwards using a diminishing radius value:
Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.DoubleBuffered = True
    End Sub
 
    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        Static R As New Random
 
        Dim C As Color
        Dim rc As Rectangle
 
        Dim center As New Point(Me.ClientRectangle.Width / 2, Me.ClientRectangle.Height / 2)
        Dim radius As Integer = Math.Min(Me.ClientRectangle.Width, Me.ClientRectangle.Height) / 2
 
        While radius > 0
            rc = New Rectangle(center.X - radius, center.Y - radius, radius * 2, radius * 2)
            C = Color.FromArgb(255, R.Next(0, 256), R.Next(0, 256), R.Next(0, 256))
            Using P As New Pen(C, 2)
                e.Graphics.DrawEllipse(P, rc)
            End Using
            radius = radius - 1
        End While
    End Sub
 
    Private Sub Form1_SizeChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.SizeChanged
        Me.Refresh()
    End Sub
 
End Class

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CircleDemo3.jpg
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Author Closing Comment

by:NerdsOfTech
ID: 31579259
Perfection! Cool effects when you resize it too! Thank you Idle_Mind once again.
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LVL 32

Expert Comment

by:Daniel Wilson
ID: 24331751
Very nice.  What I was working on used a PictureBox.  Yours is cleaner.

And I was unfamiliar with DoubleBuffered.
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.doublebuffered.aspx


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LVL 86

Expert Comment

by:Mike Tomlinson
ID: 24331803
DoubleBuffered is great...but it only works for the FORM itself.  =\

If you want to DoubleBuffer a Panel or PictureBox (basically anything else) then you have to INHERIT that control and manual use SetStyle() to properly configure it:
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.setstyle(VS.71).aspx

Something like:

    Public Class SomeThing
        Inherits SomeControl

        Public Sub New()
            Me.SetStyle(ControlStyles.OptimizedDoubleBuffer, True)
            Me.SetStyle(ControlStyles.AllPaintingInWmPaint, True)
            Me.SetStyle(ControlStyles.UserPaint, True)
            Me.UpdateStyles()
        End Sub

    End Class

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LVL 86

Expert Comment

by:Mike Tomlinson
ID: 24331921
@NerdsOfTech...thanx for the totally unexpected donation!  Much appreciated...  =)

I was playing around, just for grits and shins...try this out:
(Right Click the Form)
Public Class Form1
 
    Private CM As New ContextMenu
    Private PreviewWidth As Integer = 15
    Private PreviewMargin As Integer = 3
    Private SelectedColor As Color = Color.Cyan
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.DoubleBuffered = True
        For Each C As Color In System.ComponentModel.TypeDescriptor.GetConverter(GetType(Color)).GetStandardValues
            If Not C.IsSystemColor Then
                Dim mi As New MenuItem(C.ToKnownColor.ToString)
                mi.Tag = C.ToKnownColor
                mi.OwnerDraw = True
                AddHandler mi.MeasureItem, AddressOf mi_MeasureItem
                AddHandler mi.DrawItem, AddressOf mi_DrawItem
                AddHandler mi.Click, AddressOf mi_Click
                CM.MenuItems.Add(mi)
            End If
        Next
        Me.ContextMenu = CM
    End Sub
 
    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        Static R As New Random
 
        Dim C As Color
        Dim rc As Rectangle
        Dim percent As Double
 
        Dim center As New Point(Me.ClientRectangle.Width / 2, Me.ClientRectangle.Height / 2)
        Dim radius As Integer = Math.Min(Me.ClientRectangle.Width, Me.ClientRectangle.Height) / 2
        Dim startRadius As Integer = radius
 
        While radius > 0
            rc = New Rectangle(center.X - radius, center.Y - radius, radius * 2, radius * 2)
            percent = (startRadius - radius) / startRadius
            C = Color.FromArgb(255, percent * SelectedColor.R, percent * SelectedColor.G, percent * SelectedColor.B)
            Using P As New Pen(C, 2)
                e.Graphics.DrawEllipse(P, rc)
            End Using
            radius = radius - 1
        End While
    End Sub
 
    Private Sub Form1_SizeChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.SizeChanged
        Me.Refresh()
    End Sub
 
    Private Sub mi_MeasureItem(ByVal sender As Object, ByVal e As System.Windows.Forms.MeasureItemEventArgs)
        Dim mi As MenuItem = CType(sender, MenuItem)
        Dim sz As SizeF = e.Graphics.MeasureString(mi.Text, Me.Font)
        e.ItemHeight = sz.Height
        e.ItemWidth = sz.Width + PreviewWidth + (2 * PreviewMargin)
    End Sub
 
    Private Sub mi_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs)
        Dim mi As MenuItem = CType(sender, MenuItem)
        e.DrawBackground()
        e.Graphics.DrawString(mi.Text, Me.Font, Brushes.Black, e.Bounds.X + PreviewWidth + (2 * PreviewMargin), e.Bounds.Y)
        Dim rc As New Rectangle(e.Bounds.X + PreviewMargin, e.Bounds.Y + PreviewMargin, PreviewWidth, e.Bounds.Height - (2 * PreviewMargin))
        Using sb As New SolidBrush(Color.FromKnownColor(mi.Tag))
            e.Graphics.FillRectangle(sb, rc)
        End Using
        e.Graphics.DrawRectangle(Pens.Black, rc)
    End Sub
 
    Private Sub mi_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim mi As MenuItem = CType(sender, MenuItem)
        SelectedColor = Color.FromKnownColor(mi.Tag)
        Me.Refresh()
    End Sub
 
End Class

Open in new window

CircleDemo4.jpg
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LVL 19

Author Comment

by:NerdsOfTech
ID: 24332000
WOW! THAT is stellar! Now that... is extremely cool.
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LVL 19

Author Comment

by:NerdsOfTech
ID: 24332021
Your welcome. You deserved it.

=NerdsOfTech
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