[RESOLVED] Dynamically added usercontrol, how to remove added control from Form?

[Tech99]

How to remove (unload) dynamically added usercontrol from form?

Controls are added and placed in form, dynamically during runtime. When tried to remove, error 365 is raised.
So is it possible to remove controls, which are added during runtime.

Dim WithEvents My_UserControl As VBControlExtender  'Form level declaration

'Form subroutines
Sub AddControl ()
Set My_UserControl = Controls.Add("MyProject.My_UserControl", "My_UserControl")
My_UserControl.Top = 2250
My_UserControl.Left = 90
My_UserControl.ZOrder 0
My_UserControl.Visible = True
End Sub

Sub RemoveControl ()
Dim C As Control
    For Each C In MyForm.Controls
        If sCtlName = "My_UserControl" Then MyForm.Controls.Remove (C.Name) 'Run-time error 365 -> Unable to unload within this context.
    Next
End Sub

[gilman]

if you go through the collection through a loop for next you can not modify the collection in the loop.
Try

Sub RemoveControl()
    MyForm.Controls.Remove "My_UserControl"
End Sub

[Tech99]

Removing by referencing control name in string variable or static name, does not work either.

[CODE]
Dim WithEvents My_UserControl As VBControlExtender 'Form level declaration
Dim PreviousCtlName as string

'Form subroutines
Sub AddControl ()
Set My_UserControl = Controls.Add("MyProject.My_UserControl", "My_UserControl")
PreviousCtlName = My_UserControl.Name
My_UserControl.Top = 2250
My_UserControl.Left = 90
My_UserControl.ZOrder 0
My_UserControl.Visible = True
End Sub

Sub RemoveControl ()
If Len(PreviousCtlName) Then MyForm.Controls.Remove (PreviousCtlName) 'Run-time error 365 -> Unable to unload within this context.
'OR
MyForm.Controls.Remove ("My_UserControl") 'Run-time error 365 -> Unable to unload within this context.
End Sub

[Tech99]

double post - delete this

[Arnoutdv]

A basic sample without error checking, but does this concept work for you?

Option Explicit

Private Sub Command1_Click()
  Dim TB As TextBox
  
  Set TB = Controls.Add("VB.TextBox", "txt2")
  TB.Visible = True
  TB.Top = Command1.Top + Command1.Height * 2
  TB.Left = Command1.Left
  TB.Text = "My first textbox"
End Sub

Private Sub Command2_Click()
  RemoveControl "txt2"
End Sub

Private Sub RemoveControl(ByVal sName As String)
  Dim i As Long
  
  For i = Controls.Count - 1 To 0 Step -1
    If Controls(i).Name = sName Then Controls.Remove i
  Next i
End Sub

[Tech99]

Yes, that works with intrinsic VB controls OK, but not with usercontrols in rather large project**. I made an simple test project, where removing works ok.

 Dim WithEvents My_UserControl As VBControlExtender 'Form level declaration
 Dim PreviousCtlName as string

 'Form subroutines
 Sub AddControl ()
 Set My_UserControl = Controls.Add("MyProject.My_UserControl", "My_UserControl")
 PreviousCtlName = My_UserControl.Name
 My_UserControl.Top = 2250
 My_UserControl.Left = 90
 My_UserControl.ZOrder 0
 My_UserControl.Visible = True
 End Sub

 Sub RemoveControl ()
For i = Controls.Count - 1 To 0 Step -1
    If Controls(i).Name = PreviousCtlName Then Controls.Remove i  'Run-time error 365 -> Unable to unload within this context.
  Next i
 End Sub

MSDN document
https://docs.microsoft.com/en-us/off...text-error-365
lists possible causes, but none of them adapt to this case.

[Eduardo-]

You are probably trying to remove the control from an event of the control.

Post a sample with the problem.

And the size of the project has nothing to do for sure.

[gilman]

Removing by referencing control name in string variable or static name, does not work either.

[CODE]
Dim WithEvents My_UserControl As VBControlExtender 'Form level declaration
Dim PreviousCtlName as string

'Form subroutines
Sub AddControl ()
Set My_UserControl = Controls.Add("MyProject.My_UserControl", "My_UserControl")
PreviousCtlName = My_UserControl.Name
My_UserControl.Top = 2250
My_UserControl.Left = 90
My_UserControl.ZOrder 0
My_UserControl.Visible = True
End Sub

Sub RemoveControl ()
If Len(PreviousCtlName) Then MyForm.Controls.Remove (PreviousCtlName) 'Run-time error 365 -> Unable to unload within this context.
'OR
MyForm.Controls.Remove ("My_UserControl") 'Run-time error 365 -> Unable to unload within this context.
End Sub

I try

Option Explicit

Dim WithEvents My_UserControl As VBControlExtender  'Form level declaration
'Form subroutines
Sub AddControl()
Set My_UserControl = Controls.Add("ViasEnvio.ctlViaEnvio", "My_UserControl")
My_UserControl.Top = 2250
My_UserControl.Left = 90
My_UserControl.ZOrder 0
My_UserControl.Visible = True
End Sub

Sub RemoveControl()
Controls.Remove ("My_UserControl")
End Sub

Private Sub Form_Load()
    AddControl
    RemoveControl
    
End Sub

And works fine, the problem must be other.

[Tech99]

Eduardo, you are right, i am swithcing usercontrol from Combobox click event. Sample attached.
So how to remedy situation?
One possible solution is to add timer and boolean variable bRemovePreviousControl and execute control removing code from there.
Any other possibility without timer?

[Eduardo-]

Eduardo, you are right, i am swithcing usercontrol from Combobox click event. Sample attached.
So how to remedy situation?
One possible solution is to add timer and boolean variable bRemovePreviousControl and execute control removing code from there.
Any other possibility without timer?

Yes, with a timer. That's the way to do it. You need to decouple it from the event.

[Tech99]

Ok, thanks Eduardo. Sample solution attached.