Custom Panel Not Acting as Parent to Contained Controls

[neef]

I created a simple custom controlled Panel for double buffering. When I use the control in my toolbox it works just fine, but when I attempt to add controls inside the panel those controls aren't staying when I move the panel around. My custom panel isn't acting as the controls' parent. I verified this by looking in the designer code.

I tested a standard panel on the same form and it works perfectly normal - as I drag the parent Panel the interior controls move along with it. It is only my custom Panel which doesn't seem to detect when another control is placed within it.

Here is my constructor code:

Public Class DBPanel
    Inherits System.Windows.Forms.PictureBox
    Public Sub New()
        MyBase.New()

        SetStyle(ControlStyles.OptimizedDoubleBuffer Or ControlStyles.UserPaint Or ControlStyles.AllPaintingInWmPaint, True)
        SetStyle(ControlStyles.ResizeRedraw, True)
        Me.UpdateStyles()
    End Sub
End Class

What am I missing to get this control to behave like a regular panel?

Thanks!

[.paul.]

PictureBoxes aren't intended to be parent (container) controls.
could you use a panel + change controlstyles in that?

[.paul.]

something like this:

Public Class DBPanel
    Inherits Panel
 
    Public Sub New()
        MyBase.New()
 
        SetStyle(ControlStyles.OptimizedDoubleBuffer Or ControlStyles.UserPaint Or ControlStyles.AllPaintingInWmPaint, True)
        SetStyle(ControlStyles.ResizeRedraw, True)
        Me.UpdateStyles()
    End Sub
 
    Private _image As Image
    Public Property Image() As Image
        Get
            Return _image
        End Get
        Set(ByVal value As Image)
            _image = value
            Me.Invalidate()
        End Set
    End Property
 
    Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
        If Me.Image IsNot Nothing Then
            e.Graphics.DrawImage(Me.Image, Me.Bounds) 'stretch image
        End If
        MyBase.OnPaint(e)
    End Sub
 
End Class

[neef]

I cut an pasted the wrong custom control code - this is from my custom picturebox (which works fine). If you just replace "Inherits System.Windows.Forms.PictureBox" with "Inherits System.Windows.Forms.Panel" that would make my code accurate.

I truly apologize for the error!

[.paul.]

ok. i tried it. it worked ok for me.
is there any other code involved?

[neef]

Thanks for your efforts. The only relevant code I can think of is in the designer. What is see is this:

        Me.Controls.Add(Me.DbPanel7)
        Me.Controls.Add(Me.Label3)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.Label1)

DbPanel is the custom panel and the labels are supposed to be inside the panel. It should look like this:

        Me.Controls.Add(Me.DbPanel7)
        Me.DbPanel7.Controls.Add(Me.Label3)
        Me.DbPanel7.Controls.Add(Me.Label2)
        Me.DbPanel7.Controls.Add(Me.Label1)

No matter where I place these labels the designer falls to have them contained in my panel. I have learned the hard way never to mess with designer code, so I haven't attempted to change anything.

Very frustrating...

[.paul.]

did you add them to the form + drag them onto the panel?
all i can suggest is that you make sure the panel is focused when adding controls.

your 2nd snippet is how the designer should be + it should be ok to go ahead + change it.

[neef]

When I switched the code in the designer it switched it right back! It's almost funny how badly this code does not want to work.

One other interesting bit of information I just noticed - my custom panels do not have 4-way arrow icons in the upper left corner that regular panels possess. Whereas in a regular panel you have to drag and drop using this icon my panels can be dragged and dropped from anywhere inside the panel. Does this provide a hint?

[.paul.]

it adds to the evidence that there's something wrong, but it doesn't lead to an easy solution.