I've actually been struggling with painting with VB.Net for a few weeks. All I know is that I shouldn't use CreateGraphics if I can avoid it, so I've done just that. One of the questions comes from a CodeGolf challenge that requires users to draw sprockets.

This is only my beginning of that. I've never displayed anything I haven't drawn in excel. At first I tried a Class of sprockets, but it wouldn't fill my List properly, so I've boiled it down to

  1. populating an array
  2. passing that array to the form
  3. Painting my circles.

Essentially I read the input, convert it to integer array, send that to the form and draw the circles. I've probably made it way too complicated, but like I said, I've struggled for a few weeks, which is why I'm here. Parsing the input was pretty tricky to me, actually.


Comes in the form of (sets of) 3 integers (x-position, y-position, radius) e.g.

(0, 0, 16),  (100, 0, 16),  (100, 100, 12),  (50, 50, 24),  (0, 100, 12)


enter image description here

Standard Module

Option Explicit On
Option Strict On
Option Infer On
Option Compare Text
Imports System.IO
Module Module1
    Const INPUT_PATH As String = "C:\Temp\gearinput.txt"
    Public delimiter() As String = {"),"}
    Sub Main()
        Dim inputData() As String
        inputData = GetInput()
        Dim sprocketData() As String = Custom_Split(inputData(0))
        Dim paintingdata(,) As Integer = StringToIntArray(sprocketData)
        Dim targetForm As New Form1
        targetForm.Visible = True
        targetForm.DrawSprockets(targetForm, paintingdata)
    End Sub
    Private Function Custom_Split(ByVal stringToSplit As String) As String()
        stringToSplit = stringToSplit.Replace("(", String.Empty)
        stringToSplit = stringToSplit.Replace(" ", String.Empty)
        Dim stringArray() As String = stringToSplit.Split(delimiter, StringSplitOptions.RemoveEmptyEntries)
        stringArray(stringArray.Length - 1) = stringArray(stringArray.Length - 1).Replace(")", String.Empty)
        Return stringArray
    End Function
    Private Function StringToIntArray(ByVal sprocketdata() As String) As Integer(,)
        Dim firstDimensionSize As Integer = sprocketdata.GetUpperBound(0)
        Dim integerArray(firstDimensionSize, 2) As Integer
        Dim tempString() As String
        For i As Integer = 0 To firstDimensionSize
            tempString = sprocketdata(i).Split(","c)
            For j = 0 To 2
                integerArray(i, j) = Convert.ToInt32(tempString(j))
        Return integerArray
    End Function

    Private Function GetInput() As String()
        Return File.ReadAllLines(INPUT_PATH)
    End Function
End Module

Form Code

Imports System.Drawing
Imports System.Windows.Forms

Public Class Form1
    Const BUFFER As Integer = 20
 Dim xValue As Integer
    Dim yValue As Integer
    Dim pRadius As Integer
    Dim paintData(,) As Integer
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load

    End Sub
Public Shared Sub DrawSprockets(ByVal myForm As Form1, ByVal dataArray(,) As Integer)
        myForm.paintData = dataArray
        For i As Integer = 0 To myForm.paintData.GetUpperBound(0)
            myForm.paintData(i, 0) += 10
            myForm.paintData(i, 1) += 10
    End Sub

    Private Sub Form1_Paint(ByVal sender As Object, e As PaintEventArgs) Handles MyBase.Paint
Dim myPen As Pen

        myPen = New Pen(Brushes.Black)

        For i As Integer = 0 To paintData.GetUpperBound(0)
            e.Graphics.DrawEllipse(myPen, New Rectangle(paintData(i, 0), paintData(i, 1), paintData(i, 2), paintData(i, 2)))
            e.Graphics.FillEllipse(Brushes.Black, New Rectangle(paintData(i, 0), paintData(i, 1), paintData(i, 2), paintData(i, 2)))


    End Sub

End Class

1 Answer 1


The overall structure of your code looks good, but the readability is a tad poor. You should always strive to follow the Framework Design Guidelines. Use proper naming and add a few linebreaks.

Rather than using arrays, create a dedicated "Sprocket" class to hold the parsed input data.

Public Class Sprocket
    Public Property X As Integer
    Public Property Y As Integer
    Public Property R As Integer
End Class

Now, if you add the rest of the non-numeric characters to the separator list you could actually read and parse the file in two lines. (Though you ougth to use the line-continuation character for readability as seen at the bottom)

Dim numbers = File.ReadAllText("C:\Temp\gearinput.txt").Split($"{Environment.NewLine} ,)(".ToCharArray(), StringSplitOptions.RemoveEmptyEntries).Select(Function(n) Integer.Parse(n)).ToArray()
Dim sprockets = Enumerable.Range(0, (numbers.Length \ 3)).Select(Function(i) New Sprocket With {.X = numbers(((i * 3) + 0)), .Y = numbers(((i * 3) + 1)), .R = numbers(((i * 3) + 2))}).ToArray()



Public Class Sprocket

    Public Property X As Integer
    Public Property Y As Integer
    Public Property R As Integer

    Public Overrides Function ToString() As String
        Return $"{{ X={Me.X}, Y={Me.Y}, R={Me.R} }}"
    End Function

End Class


Public Module Program

    Public Sub Main()

        'TODO: Read file
        Dim input = "(0, 0, 16),  (100, 0, 16),  (100, 100, 12),  (50, 50, 24),  (0, 100, 12)"

        Dim numbers = input _
            .Split($"{Environment.NewLine} ,)(".ToCharArray(), StringSplitOptions.RemoveEmptyEntries) _
            .Select(Function(n) Integer.Parse(n)) _

        Dim sprockets = Enumerable _
            .Range(0, (numbers.Length \ 3)) _
            .Select(Function(i) New Sprocket With
                .X = numbers(((i * 3) + 0)),
                .Y = numbers(((i * 3) + 1)),
                .R = numbers(((i * 3) + 2))
            }) _

        Application.Run(New Window(sprockets))

    End Sub

End Module


Public Class Window
    Inherits Form

    Private ReadOnly sprockets As Sprocket()

    Public Sub New(sprockets As Sprocket())

        If (sprockets Is Nothing) Then
            Throw New ArgumentNullException(NameOf(sprockets))
        End If

        Me.sprockets = sprockets

        Me.SetStyle(ControlStyles.AllPaintingInWmPaint Or ControlStyles.UserPaint Or ControlStyles.OptimizedDoubleBuffer, True)

        Me.Text = "Sprockets"
        Me.AutoScaleMode = AutoScaleMode.Font
        Me.ClientSize = New Size(800, 450)

    End Sub

    Protected Overrides Sub OnPaint(e As PaintEventArgs)

        e.Graphics.SmoothingMode = Drawing2D.SmoothingMode.HighQuality

        For Each sprocket In Me.sprockets

            Dim diameter = (sprocket.R * 2)
            Dim rect = New Rectangle(sprocket.X, sprocket.Y, diameter, diameter)

            e.Graphics.FillEllipse(Brushes.Black, rect)


    End Sub

End Class
  • \$\begingroup\$ Thanks. Haven't had a chance to read this, but I didn't want you to think I wasn't interested! \$\endgroup\$ Mar 28, 2018 at 21:26
  • 1
    \$\begingroup\$ @Raystafarian No problem. As a side note: Your entry point (sub Main) looks a bit weird. No reference to Application.Run (the start of the message pump). Visual Studio auto-generate the entry point for VB.NET applications. But to manually wire up the start (as I did in the Program module) you do as follows: Double click "My project" in the solution pane. Click "Application" tab and uncheck "Enable application framework". Then choose "Sub Main" from the "Startup object" dropdown. \$\endgroup\$ Mar 29, 2018 at 9:32
  • \$\begingroup\$ Great, that's something I had no idea about - thanks \$\endgroup\$ Mar 30, 2018 at 8:47
  • \$\begingroup\$ With naming, the guide is basically saying everything should be PascalCase except parameters in functions, I'm reading that correctly? \$\endgroup\$ Mar 30, 2018 at 23:04
  • \$\begingroup\$ Yup. And even though the guide do not specify a convention for variables, the consensus is to use camelCase. \$\endgroup\$ Mar 31, 2018 at 7:01

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