Draw a circle that follows the mouse cursor without latent circles

I have a form and would like to have a circle follow the mouse cursor.  Similarly to what is shown in Adobe Photoshop when you are in line brush mode and you can see the size of the brush you are about to draw.  My problem occurs when I place a background image on the form.

To use the example code below.  Create form and paste the code into the form (the size of my form is 804X584).  Run the application.  Initially you will have great performance.  However if you give the form a background image.  In my situation I just used C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Blue hills.jpg and you will see some latent circles when you move the mouse very fast.  The attached picture shows you the latent circles.

I've tried using the OvalShape from Microsoft.VisualBasic.PowerPacks but the performance of that was even worse.

Some notes about the code below:
1.  I pretty draw the circle in the function ShowQualityCircle (called from MouseMove).  Here I call Invalidate without any arguments.  When I tried it with a rectangle I got a number of latent circles.  I even tried a larger rectangles but when I moved the mouse very fast I still got latent circles.
2.  Without the call to draw the circle in the Paint routine I got a number of latent rectangles, so that was necessary.

You help would be greatly appreciated.

Public Class Form1
  Private QCircle As New Rectangle(0, 0, 0, 0)
 
  Private Sub Form1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
    ShowQualityCircle((e.X), (e.Y), 20)
  End Sub
 
  Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
    If QCircle.Width > 0 AndAlso QCircle.Height > 0 Then
      DrawCircle(e.Graphics, Color.Red, QCircle.X, QCircle.Y, QCircle.Width, QCircle.Height, 0, 360)
    End If
  End Sub
 
  Private Sub DrawCircle(ByRef g As Graphics, ByVal currentColor As Color, ByVal x As Single, ByVal y As Single, ByVal width As Single, ByVal height As Single, ByVal startAngle As Single, ByVal sweepAngle As Single)
    Dim myBrush As New SolidBrush(currentColor)
    Dim myPen As New Pen(myBrush)
    myPen.Width = 1
    g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias
    g.DrawArc(myPen, x, y, width, height, startAngle, sweepAngle)
  End Sub
 
  Private Sub ShowQualityCircle(ByVal imgX As Integer, ByVal imgY As Integer, ByVal mypenradius As Integer)
    QCircle = New Rectangle(imgX - mypenradius, imgY - mypenradius, mypenradius * 2, mypenradius * 2)
    Dim g As Graphics = Me.CreateGraphics()
    DrawCircle(g, Color.Red, QCircle.X, QCircle.Y, QCircle.Width, QCircle.Height, 0, 360)
    g.Dispose()
    'Me.Refresh()
    Me.Invalidate()
  End Sub
End Class

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doublecircle.png
tedunniAsked:
Who is Participating?
 
Mike TomlinsonConnect With a Mentor Middle School Assistant TeacherCommented:
Create a CURSOR instead of trying to draw that puppy all over the place...  ;)
Public Class Form1
 
    Private radius As Integer = 20
    Private startAngle As Integer = 0
    Private sweepAngle As Integer = 360
    Private currentColor As Color = Color.Red
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        CreateCursor()
    End Sub
 
    Private Sub CreateCursor()
        Dim bmp As New Bitmap(radius * 2, radius * 2)
        Dim g As Graphics = Graphics.FromImage(bmp)
        Dim myPen As New Pen(currentColor, 1)
        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias
        g.DrawArc(myPen, 0, 0, bmp.Width - 1, bmp.Height - 1, startAngle, sweepAngle)
        g.Dispose()
        myPen.Dispose()
 
        Dim C As New Cursor(bmp.GetHicon)
        Me.Cursor = C
    End Sub
 
End Class

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tedunniAuthor Commented:
Thanks, this solution is perfect.
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tedunniAuthor Commented:
Idle_Mind, I'm going to ask a related question regarding this, but if I were to have a radius of say 48 it only draws part of the circle.  Additionally, if the radius gets quite large (try 576), then I get a GDI+ exception.  Any suggestions.  

Btw, the related question wizard keeps asking me to assign a title for the question (Even when I assign one), and so I'm posting here but once I get that figured out I'll post the link to the related question.
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tedunniAuthor Commented:
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