[RESOLVED] [2005] Panel container on UserControl

[HanneSThEGreaT]

Hello everyone.
I have a usercontrol, and on the usercontrol I have a Panel.
What I want to do is to make the Panel the host for child controls, In other words, I want to add ( in design View ) controls to the panel on the usercontrol.
I did this in my layout event:

    Private Sub HTG_Group_Layout(ByVal sender As Object, ByVal e As System.Windows.Forms.LayoutEventArgs) Handles Me.Layout
        Try

            If e.AffectedControl.Name <> Me.Name And e.AffectedControl.Name <> pnlGBBody.Name And e.AffectedControl.Name <> lblGBHead.Name Then

                Select Case e.AffectedControl.Top
                    Case pnlGBBody.Top To pnlGBBody.Top + pnlGBBody.Height

                        Select Case e.AffectedControl.Left
                            Case pnlGBBody.Left To pnlGBBody.Left + pnlGBBody.Width

                                If e.AffectedProperty.ToString() = "Bounds" Then

                                    'set the parent 
                                    e.AffectedControl.Parent = pnlGBBody
                                    pnlGBBody.Controls.Add(e.AffectedControl)
                                    'calculate the top & left to drop it where the user intended 
                                    e.AffectedControl.Top = e.AffectedControl.Top - pnlGBBody.Top
                                    e.AffectedControl.Left = e.AffectedControl.Left - pnlGBBody.Left
                                    e.AffectedControl.PerformLayout()
                                End If

                        End Select

                End Select

            End If
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

Yes, it does add the controls to the panel, but, the moment I move any of the child controls, I get an error that the control I've added is disabled because there is no reference set to an instance of an object.
How do I catch it, how can I get over it ¿

Any help will be greatly appreciated.

[GremlinSA]

I'd say that there is code missing from the designer class of the form ...

check the designer code to see that there is full reference to each child control

        Friend WithEvents Button2 As System.Windows.Forms.Button

        Private Sub InitializeComponent()
            Me.Button2 = New System.Windows.Forms.Button

            Me.UserControl.Controls.Add(Me.Button2)

            '
            'Button2
            '
            Me.Button2.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)
            Me.Button2.Location = New System.Drawing.Point(6, 194)
            Me.Button2.Name = "Button2"
            Me.Button2.Size = New System.Drawing.Size(91, 28)
            Me.Button2.TabIndex = 6
            Me.Button2.Text = "Add"
            Me.Button2.UseVisualStyleBackColor = True

Above is just an example of all the Designer code required to add it to a object already on the form ...

Also your Usercontrol will need simular code in the designer..

Gremmy...

[HanneSThEGreaT]

Thanx Gremmy, I get what you're saying - the child control needs to be initialised.
Problem is, when I drag a button ( for example ) from the Toolbox in Design view, onto the usercontrol, it works, but the moment I move the button ( still in design view ), it gives me that error.
Doesn't make sense to my thick head

[GremlinSA]

One thing to remember, Designer code is called such, because it does run at design time. unfortunately you cannot trap it..

I'd check in your usercontrol how you are handeling the 'Controls.Add()' bit, i'm taking a guess that the problem may be there somewhere, and my guess is that your missing that one vital keyword , "NEW" ... ..

Gremmy...

[HanneSThEGreaT]

I am such an idiot!
Somebody please just come and knock some sense into me LOL!
Gremmy, this is what I did:

   Private Sub HTG_Group_Layout(ByVal sender As Object, ByVal e As System.Windows.Forms.LayoutEventArgs) Handles Me.Layout
        Try
            Dim i As New Control
            i = e.AffectedControl
            If i.Name <> Me.Name And i.Name <> pnlGBBody.Name And i.Name <> lblGBHead.Name Then

                Select Case i.Top
                    Case pnlGBBody.Top To pnlGBBody.Top + pnlGBBody.Height

                        Select Case i.Left
                            Case pnlGBBody.Left To pnlGBBody.Left + pnlGBBody.Width

                                If i.ToString() = "Bounds" Then

                                    'set the parent 
                                    i.Parent = pnlGBBody
                                    pnlGBBody.Controls.Add(i)
                                    'calculate the top & left to drop it where the user intended 
                                    i.Top = e.AffectedControl.Top - pnlGBBody.Top
                                    i.Left = e.AffectedControl.Left - pnlGBBody.Left
                                    i.PerformLayout()
                                End If

                        End Select

                End Select

            End If
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

It works.
Man, I can't wait for the weekend to begin.
Gremmy, I can't rate you yet

[GremlinSA]

Hmm i see what happened there .. you can work with 'e' directly.. Have to use 'NEW' ..

Well i'm glad you got it all working again ...

As with the reps, in time ...

Cheers..

[HanneSThEGreaT]

Spoke too soon.
If I do this, as it should be:

  Private Sub HTG_Group_Layout(ByVal sender As Object, ByVal e As System.Windows.Forms.LayoutEventArgs) Handles Me.Layout

        Try
            Dim i As New Control
            i = e.AffectedControl
            If i.Name <> Me.Name And i.Name <> pnlGBBody.Name And i.Name <> lblGBHead.Name Then

                Select Case i.Top
                    Case pnlGBBody.Top To pnlGBBody.Top + pnlGBBody.Height

                        Select Case i.Left
                            Case pnlGBBody.Left To pnlGBBody.Left + pnlGBBody.Width

                                If e.AffectedProperty.ToString() = "Bounds" Then

                                    'set the parent 
                                    i.Parent = pnlGBBody
                                    pnlGBBody.Controls.Add(i)
                                    '                                'calculate the top & left to drop it where the user intended 
                                    i.Top = e.AffectedControl.Top - pnlGBBody.Top
                                    i.Left = e.AffectedControl.Left - pnlGBBody.Left
                                    i.PerformLayout()
                                End If

                        End Select

                End Select

            End If
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        End Try
    End Sub

It still happens

Let me rather make a separate Panel control, then add it to the main usercontrol - that should work

[HanneSThEGreaT]

Ok, it seems that not enough sleep and just plain common stupidity ( mine ) has caused this

Having a panel with scrollbar on the usercontrol is overkill, the usercontrol already Inherits from Scrollable control, so meaning, I am able to set its AutoScroll to true with all the autoscrollmargins properties as well

So, all I ended up doing with the usercontrol was this :

Imports System.ComponentModel
Imports System.ComponentModel.Design
<Designer("System.Windows.Forms.Design.ParentControlDesigner,System.Design", GetType(IDesigner))> _
Public Class Blah

This makes the usercontrol a container, meaning all controls added will be children