Unable to set a property...

[YourSurrogateGod]

This is really odd. I went through this class with a debugger and after the constructor was called and the variables were assigned, the min and max were both -1 ? What am I screwing up?

Option Strict On
Option Explicit On 

Public Class drawing_graph
  Private max As Integer
  Private min As Integer
  Private difference As Integer
  Private gr As graphics
  Private point_keeper As ArrayList
  Private d_panel As Panel

  Public Property maximum() As Integer
    Get
      Return max
    End Get
    Set(ByVal Value As Integer)
      If Value < Me.minimum Then
        max = Me.minimum + 1
        Exit Property
      End If


      max = Value
    End Set
  End Property
  Public Property minimum() As Integer
    Get
      Return min
    End Get
    Set(ByVal Value As Integer)
      If Value > Me.maximum Then
        min = Me.maximum - 1
        Exit Property
      End If

      min = Value
    End Set
  End Property
  Private Property graphics() As graphics
    Get
      Return gr
    End Get
    Set(ByVal Value As graphics)
      If Value Is Nothing Then
        Throw New Exception("The passed in graphics was not allocated.")
        Exit Property
      End If

      gr = Value
    End Set
  End Property
  WriteOnly Property draw_panel() As Panel
    Set(ByVal Value As Panel)
      d_panel = Value
    End Set
  End Property

  Sub New(ByVal gr As graphics, ByRef panel As Panel)
    Try
      Me.graphics = gr
    Catch ex As Exception
      MessageBox.Show(ex.Message, "Warning!", MessageBoxButtons.OK, MessageBoxIcon.Error)
    End Try

    Try
      Me.draw_panel = panel
    Catch ex As Exception
      MessageBox.Show(ex.Message, "Warning!", MessageBoxButtons.OK, MessageBoxIcon.Error)
    End Try

    Me.maximum = 0
    Me.minimum = 30

    difference = Me.maximum - Me.minimum
  End Sub

  Public Sub draw(ByVal val As Integer)
    If val > Me.maximum Then
      val = Me.maximum
    ElseIf val < Me.minimum Then
      val = Me.minimum
    End If

    point_keeper.Add(val)
    If point_keeper.Count = 30 Then
      point_keeper.RemoveAt(point_keeper.Count - 1)
    End If

    clear()
    sub_draw()
  End Sub

  Private Sub clear()
    gr.Clear(Color.Azure)
  End Sub

  Private Sub sub_draw()
    Const num_hlines As Double = 30.0
    Dim line_points(point_keeper.Count) As Point

    For i As Integer = 0 To point_keeper.Count
      line_points(i) = New Point(CType(CType(d_panel.Width, Double) - _
      ((CType(d_panel.Width, Double) / num_hlines) * CType(i, Double)), Integer), _
      CType(point_keeper(0), Integer))
    Next

    gr.DrawLines(Pens.Red, line_points)
  End Sub
End Class

[Boumxyz2]

here's the problem,

these 2 lines in the constructor

will call the PROPERTY and not the data member

now you set max to 0 will go throug ok

Me.maximum = 0

but this
Me.minimum = 30

will get you inside your IF statement.

If Value > Me.maximum Then
min = Me.maximum - 1
Exit Property
End If

that's why you get -1

hope it helps

[YourSurrogateGod]

That was a stupid mistake. Thanks.

[Boumxyz2]

hehe I guess you just inverted Max and min