Thanks for sharing.
I have tweaked it a bit more with original BackColor, DoubleBuffering and 3 new properties (DrawRightToLeft, GraphLineColor and GraphLineThickness) and here is the code:
Imports System
Imports System.ComponentModel
Public Class BasicTrendChartEx
Inherits BasicTrendChart
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
'* Fill in the background color
Me.DoubleBuffered = True 'Reduce or eliminate flicker
e.Graphics.FillRectangle(New SolidBrush(BackColor), 0, 0, Me.Width, Me.Height)
Dim x1, y1 As Integer
Dim x2, y2 As Integer
'* Draw the line connecting the points
If Points.Count > 1 Then
Dim index As Integer = 0
While index < (Points.Count - 2)
Try
'* calculate the x and y coordinates based on the Points collection
If DrawRightToLeft = True Then
x1 = Me.Width - Convert.ToInt32((Me.Width / MaxPoints) * index)
x2 = Me.Width - Convert.ToInt32((Me.Width / MaxPoints) * (index + 1))
Else
x1 = Convert.ToInt32((Me.Width / MaxPoints) * index)
x2 = Convert.ToInt32((Me.Width / MaxPoints) * (index + 1))
'*^ this was y1
End If
y1 = Me.Height - Convert.ToInt32((Me.Height / (YMaximum - YMinimum)) * (Points(index) - YMinimum))
y2 = Me.Height - Convert.ToInt32((Me.Height / (YMaximum - YMinimum)) * (Points(index + 1) - YMinimum))
e.Graphics.DrawLine(New Pen(GraphLineColor, GraphLineThickness), x1, y1, x2, y2)
Catch ex As Exception
Dim dbg = 0
End Try
index += 1
End While
e.Graphics.DrawString(Now.ToString("dd-MMM-yy HH:mm:ss"), New Drawing.Font("Arial", 10), System.Drawing.Brushes.White, Me.Width - 116, Me.Height - 16)
e.Graphics.DrawString(Points.Last.ToString, New Drawing.Font("Arial", 10), System.Drawing.Brushes.White, Me.Width - 40, 0)
End If
'* Draw the Axis
e.Graphics.DrawLine(System.Drawing.Pens.White, 0, 0, 0, Me.Height)
e.Graphics.DrawLine(System.Drawing.Pens.White, 0, Me.Height - 1, Me.Width, Me.Height - 1)
e.Graphics.DrawString(YMaximum.ToString, New Drawing.Font("Arial", 10.0!), System.Drawing.Brushes.White, 0.0!, 0.0!)
'* ^^^^^^^^^^^^^^^ this was MaxValue
e.Graphics.DrawString(YMinimum.ToString, New Drawing.Font("Arial", 10), System.Drawing.Brushes.White, 0, Me.Height - 16)
End Sub
Public Property DrawRightToLeft As Boolean = False
<DefaultValue(GetType(Color), "Black")> _
Public Overridable Shadows Property BackColor() As Color
Get
Return MyBase.BackColor
End Get
Set(ByVal value As Color)
MyBase.BackColor = value
Refresh()
End Set
End Property
Private _GraphLineColor As Drawing.Color = Drawing.Color.Blue
Public Property GraphLineColor() As Drawing.Color
Get
Return _GraphLineColor
End Get
Set(ByVal value As Drawing.Color)
_GraphLineColor = value
End Set
End Property
Private _gLineThickness As Single = 1
Public Property GraphLineThickness() As Single
Get
Return _gLineThickness
End Get
Set(ByVal value As Single)
If Not IsNumeric(value) Then
MsgBox("Valid values are numbers 1 to 3!")
_gLineThickness = 1
Exit Property
Else
If (value > 3) OrElse (value < 1) Then
MsgBox("Valid values are numbers 1 to 3!")
_gLineThickness = 1
Exit Property
End If
End If
_gLineThickness = value
End Set
End Property
End Class
It also shows Date/Time and the last Value.
