Graphics Problem vb2010 express

Question

I am trying to learn how to draw/shape in vb2010. The first code example is from a book, "VB2010 Step by Step". The second and third are from MSDN.

Public Class Form1
    Dim GraphicsFun As Graphics
    Dim PenColor As New Pen(Color.Red)
    GraphicsFun = Me.CreateGraphics
    GraphicsFun.DrawLine(PenColor,20,30,100,80)

    Dim pen As New Pen(Color.FromArgb(255, 0, 0, 0))
      e.Graphics.DrawLine(pen, 20, 10, 300, 100)

    Private Sub DrawRectangle()
        Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red)
        Dim formGraphics As System.Drawing.Graphics
        formGraphics = Me.CreateGraphics()
        formGraphics.DrawRectangle(myPen, New Rectangle(0, 0, 200, 300))
        myPen.Dispose()
        formGraphics.Dispose()
    End Sub

End Class

In the first two errors are "Declaration expected", GraphicsFun and e respectively.

On the third bit of code runs but I thought I would get a rectangle. I get a Blank form

Questions:
1. What am i missing, doing wrong?

2. what does "e" stand for?

3. Why do I get a blank form?

Vulpes · Answer

You have some code missing there. It's difficult to know exactly what's missing but you should see a couple of lines and a rectangle drawn on your form if you change the code as below. Note that the 'skeleton' handler for the Form1_Paint event should be added by double clicking on the Paint event in the Form's Properties Box in Visual Studio. The code can then be pasted into the skeleton handler. 'e' is the PaintEventArgs parameter to this handler. The DrawLine method can just be inserted manually. The Paint handler will be called automatically when the form loads but you need to call both DrawLine and DrawRectangle explicitly for them to do anything. Public Class Form1 Private Sub DrawLine() Dim GraphicsFun As Graphics Dim PenColor As New Pen(Color.Red) GraphicsFun = Me.CreateGraphics GraphicsFun.DrawLine(PenColor 20 30 100 80) GraphicsFun.Dispose() End Sub Private Sub DrawRectangle() Dim myPen As New System.Drawing.Pen(System.Drawing.Color.Red) Dim formGraphics As System.Drawing.Graphics formGraphics = Me.CreateGraphics() formGraphics.DrawRectangle(myPen New Rectangle(0 0 200 300)) myPen.Dispose() formGraphics.Dispose() End Sub Private Sub Form1_Paint(ByVal sender As System.Object ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint Dim pen As New Pen(Color.FromArgb(255 0 0 0)) e.Graphics.DrawLine(pen 20 10 300 100) DrawLine() DrawRectangle() End Sub End Class