Drawing a Bar Chart

Imports System.Drawing.Drawing2D
Public Class Form1
    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

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

    '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()
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(744, 502)
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None
        Me.Name = "Form1"
        Me.Text = "Form1"

    End Sub

#End Region
    Dim blnFormLoaded As Boolean = False
    Dim objHashTableG1 As New Hashtable(10)
    Dim objHashTableG2 As New Hashtable(100)

    Dim objColorArray(150) As Brush
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Try
            Dim intMaxWidth As Integer
            Dim intMaxHeight As Integer
            Dim intXaxis As Integer
            Dim intYaxis As Integer
            LoadColorArray()
            intMaxHeight = CType((Me.Height / 4) - (Me.Height / 12), Integer)
            intMaxWidth = CType(Me.Width - (Me.Width / 4), Integer)
            intXaxis = CType(Me.Width / 12, Integer)
            intYaxis = CType(Me.Height / 4, Integer)
            objHashTableG1.Add("Product1", 5)
            objHashTableG1.Add("Product2", 15)
            objHashTableG1.Add("Product3", 25)
            drawBarChart(objHashTableG1.GetEnumerator, objHashTableG1.Count, "Graph 1", intXaxis, intYaxis, intMaxWidth, intMaxHeight, True, False)
            intMaxHeight = CType((Me.Height * 0.67) - (Me.Height / 12), Integer)
            intYaxis = CType(Me.Height - (Me.Height / 12), Integer)
            objHashTableG2.Add("Item1", 50)
            objHashTableG2.Add("Item2", 150)
            objHashTableG2.Add("Item3", 250)
            objHashTableG2.Add("Item4", 20)
            objHashTableG2.Add("Item5", 100)
            objHashTableG2.Add("Item6", 125)
            objHashTableG2.Add("Item7", 148)
            objHashTableG2.Add("Item8", 199)
            objHashTableG2.Add("Item9", 267)
            drawBarChart(objHashTableG2.GetEnumerator, objHashTableG2.Count, "Graph 2", intXaxis, intYaxis, intMaxWidth, intMaxHeight, False)
            blnFormLoaded = True
        Catch ex As Exception
            Throw ex
        End Try
        
    End Sub

    Public Sub drawBarChart(ByVal objEnum As IDictionaryEnumerator, ByVal intItemCount As Integer, ByVal strGraphTitle As String, ByVal Xaxis As Integer, ByVal Yaxis As Integer, ByVal MaxWidth As Int16, ByVal MaxHt As Int16, ByVal clearForm As Boolean, Optional ByVal SpaceRequired As Boolean = False)

        Dim intGraphXaxis As Integer = Xaxis
        Dim intGraphYaxis As Integer = Yaxis
        Dim intWidthMax As Integer = MaxWidth
        Dim intHeightMax As Integer = MaxHt
        Dim intSpaceHeight As Integer
        Dim intMaxValue As Integer = 0
        Dim intCounter As Integer
        Dim intBarWidthMax
        Dim intBarHeight
        Dim strText As String
        Try
            Dim grfx As Graphics = CreateGraphics()
            If clearForm = True Then
                grfx.Clear(BackColor)
            End If

            grfx.DrawString(strGraphTitle, New Font("VERDANA", 12.0, FontStyle.Bold, GraphicsUnit.Point), Brushes.DeepPink, intGraphXaxis + (intWidthMax / 4), (intGraphYaxis - intHeightMax) - 40)

            'Get the Height of the Bar        
            intBarHeight = CInt(intHeightMax / intItemCount)

            'Get the space Height of the Bar 
            intSpaceHeight = CInt((intHeightMax / (intItemCount - 1)) - intBarHeight)

            'Find Maximum of the input value
            If Not objEnum Is Nothing Then
                While objEnum.MoveNext = True
                    If objEnum.Value > intMaxValue Then
                        intMaxValue = objEnum.Value
                    End If
                End While
            End If

            'Get the Maximum Width of the Bar
            intBarWidthMax = CInt(intWidthMax / intMaxValue)

            ' Obtain the Graphics object exposed by the Form.

            If Not objEnum Is Nothing Then
                intCounter = 1
                objEnum.Reset()
                'Draw X axis and Y axis lines
                'grfx.DrawLine(Pens.Black, intGraphXaxis, intGraphYaxis, intGraphXaxis + intWidthMax, intGraphYaxis)
                'grfx.DrawLine(Pens.Black, intGraphXaxis, intGraphYaxis, intGraphXaxis, (intGraphYaxis - intHeightMax) - 25)

                While objEnum.MoveNext = True
                    'Get new Y axis
                    intGraphYaxis = intGraphYaxis - intBarHeight
                    'Draw Rectangle
                    grfx.DrawRectangle(Pens.Black, New Rectangle(intGraphXaxis, intGraphYaxis, intBarWidthMax * objEnum.Value, intBarHeight))
                    'Fill Rectangle
                    grfx.FillRectangle(objColorArray(intCounter), New Rectangle(intGraphXaxis, intGraphYaxis, intBarWidthMax * objEnum.Value, intBarHeight))
                    'Display Text and value
                    strText = "(" & objEnum.Key & "," & objEnum.Value & ")"
                    grfx.DrawString(strText, New Font("VERDANA", 8.0, FontStyle.Regular, GraphicsUnit.Point), Brushes.Black, intGraphXaxis + (intBarWidthMax * objEnum.Value), intGraphYaxis)
                    intCounter += 1
                    If SpaceRequired = True Then
                        intGraphYaxis = intGraphYaxis - intSpaceHeight
                    End If
                    If intCounter > objColorArray.GetUpperBound(0) Then
                        intCounter = 1
                    End If
                End While
                If clearForm = True Then
                    grfx.Dispose()
                End If
            End If
        Catch ex As Exception
            Throw ex
        End Try
    End Sub

    Public Sub LoadColorArray()
        objColorArray(1) = Brushes.Blue
        objColorArray(2) = Brushes.Pink
        objColorArray(3) = Brushes.Brown
        objColorArray(4) = Brushes.BurlyWood
        objColorArray(5) = Brushes.CadetBlue
        objColorArray(6) = Brushes.Chartreuse
        objColorArray(7) = Brushes.Chocolate
        objColorArray(8) = Brushes.Coral
        objColorArray(9) = Brushes.CornflowerBlue
        objColorArray(10) = Brushes.Cornsilk
        objColorArray(11) = Brushes.Crimson
        objColorArray(12) = Brushes.Cyan
        objColorArray(13) = Brushes.DarkBlue
        objColorArray(14) = Brushes.DarkCyan
        objColorArray(15) = Brushes.DarkGoldenrod
        objColorArray(16) = Brushes.DarkGray
        objColorArray(17) = Brushes.DarkGreen
        objColorArray(18) = Brushes.DarkKhaki
        objColorArray(19) = Brushes.DarkMagenta
        objColorArray(20) = Brushes.DarkOliveGreen
        objColorArray(21) = Brushes.DarkOrange
        objColorArray(22) = Brushes.DarkOrchid
        objColorArray(23) = Brushes.DarkRed
        objColorArray(24) = Brushes.DarkSalmon
        objColorArray(25) = Brushes.DarkSeaGreen
        objColorArray(26) = Brushes.DarkSlateBlue
        objColorArray(27) = Brushes.DarkSlateGray
        objColorArray(28) = Brushes.DarkTurquoise
        objColorArray(29) = Brushes.DarkViolet
        objColorArray(30) = Brushes.DeepPink
        objColorArray(31) = Brushes.DeepSkyBlue
        objColorArray(32) = Brushes.DimGray
        objColorArray(33) = Brushes.DodgerBlue
        objColorArray(34) = Brushes.Firebrick
        objColorArray(35) = Brushes.FloralWhite
        objColorArray(36) = Brushes.ForestGreen
        objColorArray(37) = Brushes.Fuchsia
        objColorArray(38) = Brushes.Gainsboro
        objColorArray(39) = Brushes.GhostWhite
        objColorArray(40) = Brushes.Gold
        objColorArray(41) = Brushes.Goldenrod
        objColorArray(42) = Brushes.Gray
        objColorArray(43) = Brushes.Green
        objColorArray(44) = Brushes.GreenYellow
        objColorArray(45) = Brushes.Honeydew
        objColorArray(46) = Brushes.HotPink
        objColorArray(47) = Brushes.IndianRed
        objColorArray(48) = Brushes.Indigo
        objColorArray(49) = Brushes.Ivory
        objColorArray(50) = Brushes.Khaki
        objColorArray(51) = Brushes.Lavender
        objColorArray(52) = Brushes.LavenderBlush
        objColorArray(53) = Brushes.LawnGreen
        objColorArray(54) = Brushes.LemonChiffon
        objColorArray(55) = Brushes.LightBlue
        objColorArray(56) = Brushes.LightCoral
        objColorArray(57) = Brushes.LightCyan
        objColorArray(58) = Brushes.LightGoldenrodYellow
        objColorArray(59) = Brushes.LightGray
        objColorArray(60) = Brushes.LightGreen
        objColorArray(61) = Brushes.LightPink
        objColorArray(62) = Brushes.LightSalmon
        objColorArray(63) = Brushes.LightSeaGreen
        objColorArray(64) = Brushes.LightSkyBlue
        objColorArray(65) = Brushes.LightSlateGray
        objColorArray(66) = Brushes.LightSteelBlue
        objColorArray(67) = Brushes.LightYellow
        objColorArray(68) = Brushes.Lime
        objColorArray(69) = Brushes.LimeGreen
        objColorArray(70) = Brushes.Linen
        objColorArray(71) = Brushes.Magenta
        objColorArray(72) = Brushes.Maroon
        objColorArray(73) = Brushes.MediumAquamarine
        objColorArray(74) = Brushes.MediumBlue
        objColorArray(75) = Brushes.MediumOrchid
        objColorArray(76) = Brushes.MediumPurple
        objColorArray(77) = Brushes.MediumSeaGreen
        objColorArray(78) = Brushes.MediumSlateBlue
        objColorArray(79) = Brushes.MediumSpringGreen
        objColorArray(80) = Brushes.MediumTurquoise
        objColorArray(81) = Brushes.MediumVioletRed
        objColorArray(82) = Brushes.MidnightBlue
        objColorArray(83) = Brushes.MintCream
        objColorArray(84) = Brushes.MistyRose
        objColorArray(85) = Brushes.Moccasin
        objColorArray(86) = Brushes.NavajoWhite
        objColorArray(87) = Brushes.Navy
        objColorArray(88) = Brushes.OldLace
        objColorArray(89) = Brushes.Olive
        objColorArray(90) = Brushes.OliveDrab
        objColorArray(91) = Brushes.Orange
        objColorArray(92) = Brushes.OrangeRed
        objColorArray(93) = Brushes.Orchid
        objColorArray(94) = Brushes.PaleGoldenrod
        objColorArray(95) = Brushes.PaleGreen
        objColorArray(96) = Brushes.PaleTurquoise
        objColorArray(97) = Brushes.PaleVioletRed
        objColorArray(98) = Brushes.PapayaWhip
        objColorArray(99) = Brushes.PeachPuff
        objColorArray(100) = Brushes.Peru
        objColorArray(101) = Brushes.Pink
        objColorArray(102) = Brushes.Plum
        objColorArray(103) = Brushes.PowderBlue
        objColorArray(104) = Brushes.Purple
        objColorArray(105) = Brushes.Red
        objColorArray(106) = Brushes.RosyBrown
        objColorArray(107) = Brushes.RoyalBlue
        objColorArray(108) = Brushes.SaddleBrown
        objColorArray(109) = Brushes.Salmon
        objColorArray(110) = Brushes.SandyBrown
        objColorArray(111) = Brushes.SeaGreen
        objColorArray(112) = Brushes.SeaShell
        objColorArray(113) = Brushes.Sienna
        objColorArray(114) = Brushes.Silver
        objColorArray(115) = Brushes.SkyBlue
        objColorArray(116) = Brushes.SlateBlue
        objColorArray(117) = Brushes.SlateGray
        objColorArray(118) = Brushes.Snow
        objColorArray(119) = Brushes.SpringGreen
        objColorArray(120) = Brushes.SteelBlue
        objColorArray(121) = Brushes.Tan
        objColorArray(122) = Brushes.Teal
        objColorArray(123) = Brushes.Thistle
        objColorArray(124) = Brushes.Tomato
        objColorArray(125) = Brushes.Transparent
        objColorArray(126) = Brushes.Turquoise
        objColorArray(127) = Brushes.Violet
        objColorArray(128) = Brushes.Wheat
        objColorArray(129) = Brushes.White
        objColorArray(130) = Brushes.WhiteSmoke
        objColorArray(131) = Brushes.Yellow
        objColorArray(132) = Brushes.YellowGreen
    End Sub
    Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Resize
        If blnFormLoaded = True Then
            Form1_Paint(Me, New System.Windows.Forms.PaintEventArgs(CreateGraphics(), New System.Drawing.Rectangle(0, 0, Me.Width, Me.Height)))
        End If
    End Sub
End Class