Bit Map Images Under A Panel

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VB

VB10

I am trying to draw random patterns in a picture box that has a black panel over the surface hiding the drawing below. But when I make the panel disappear (panel.visible = false), the graphics in the picture box UNDER the panel are also erased. In the code below (most of which was grabbed from a VB10 book) the process works if I put the for...next loop creating the ellipses in the Private Sub picCanvas_MouseMove. The random ellipse patterns persist when the Hide Panel Button is clicked. But if I create the ellipse patterns in the Private Sub MakeGraphics_Click (click a button on the form), the ellipse patterns under the panel are erased when the panel.visible = false.

In my program I do not need the mouse down, etc events to draw squiggly lines, I only need to create the graphics when a form button is clicked.
I am probably missing something with representing the bmp where the images are stored but I am not sure what.

Thanks for any help!!!
Gary V

Public Class Form1
    Dim PenColor As New Pen(Color.Red, 2)
    Dim X As Long  ' x,y,w,h set the random position of the ellipses
    Dim Y As Long
    Dim W As Long
    Dim H As Long
    ' The Bitmap and Graphics objects we will draw on.
    Private m_Bitmap As Bitmap
    Private m_Graphics As Graphics
    ' Used for scribbling.
    Private m_Drawing As Boolean
    Private m_X As Integer
    Private m_Y As Integer

    ' Make the initial blank image.
    Private Sub Form1_Load() Handles MyBase.Load
        Call MakeNewBitmap()
    End Sub

    ' Make a new blank image.
    Private Sub mnuFileClear_Click() Handles mnuFileClear.Click
        Call MakeNewBitmap()
    End Sub

    ' Make a new Bitmap to fit the canvas.
    Private Sub MakeNewBitmap()
        ' Get the drawing surface's size.
        Dim wid As Integer = picCanvas.ClientSize.Width
        Dim hgt As Integer = picCanvas.ClientSize.Height

        ' Make a Bitmap and Graphics to fit.
        m_Bitmap = New Bitmap(wid, hgt)
        m_Graphics = Graphics.FromImage(m_Bitmap)

        ' Clear the drawing area.
        m_Graphics.Clear(Me.BackColor)

        ' Display the result.
        picCanvas.Image = m_Bitmap
    End Sub

    ' Start scribbling.
    Private Sub picCanvas_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles picCanvas.MouseDown
        m_Drawing = True
        m_X = e.X
        m_Y = e.Y
      
    End Sub

    ' Continue scribbling.
    Private Sub picCanvas_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles picCanvas.MouseMove
        If Not m_Drawing Then Exit Sub

        'For testing Purposes: Make some random elipses on screen on MouseMove

        For Temp = 1 To 8
            Randomize()
            X = 5 + (Rnd() * (m_Bitmap.Width - 30))
            Y = 5 + (Rnd() * (m_Bitmap.Height - 30))
            H = 2 + (Rnd() * 20)
            W = 2 + (Rnd() * 20)
            m_Graphics.DrawEllipse(PenColor, X, Y, W, H)
        Next

        m_Graphics.DrawLine(Pens.Black, m_X, m_Y, e.X, e.Y)
        m_X = e.X
        m_Y = e.Y
        ' Display the result.
        picCanvas.Refresh()
    End Sub

' Stop scribbling.
    Private Sub picCanvas_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles picCanvas.MouseUp
        m_Drawing = False
    End Sub

    Private Sub MakeGraphics_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MakeGraphics.Click
        'Make some random ellipses on screen when button is clicked
        m_Graphics = picCanvas.CreateGraphics
        For Temp = 1 To 8
            Randomize()
            X = 5 + (Rnd() * (picCanvas.Width - 30))
            Y = 5 + (Rnd() * (picCanvas.Height - 30))
            'Minimum length,width = 20, max = 220
            H = 2 + (Rnd() * 20)
            W = 2 + (Rnd() * 20)
            m_Graphics.DrawEllipse(PenColor, X, Y, W, H)
        Next
    End Sub

    Private Sub HidePanel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles HidePanel.Click
        If Panel1.Visible = True Then Panel1.Visible = False Else Panel1.Visible = True
    End Sub
End Class