[Gambas-user] Removing a runtime created control

[Rolf-Werner Eilert]

Am 27.11.20 um 11:34 schrieb KKing:
> I've just run the following code in 3.12.2 on Debian10 LXDE and Debian10 
> KDE.
> NB I'm creating as just "Graphical Application" (i.e. not QT or GTK)
>   - - - - - -
> Private hToolButton As ToolButton
> 
> Public Sub btnTest_Click()
>    Dim intIndex As Integer
>    For intIndex = 0 To 2
>      hToolButton = New ToolButton(Me) As "My_Button"
>      hToolButton.Top = 0 + (intIndex * 30)
>      hToolButton.Left = 0
>      hToolButton.Width = 300
>      hToolButton.Height = 30
>      hToolButton.Text = "MyButton" & CStr(intIndex)
>    Next
> End
> 
> Public Sub btnRemove_Click()
> 
>    Me["My_Button"].Delete
> 
> End
> 
> Public Sub My_Button_Click()
> 
>    Message.Info("Hello")
> 
> End
>   - - - - - -
> 
> On LXDE the btnTest generates the 3 buttons
> click btnRemove once removes the first drawn button the remaining 
> buttons still function
> click again and it removes the second drawn button the remaining button 
> still functions
> click again and it removes the third and last drawn button.
> 
> *** How could I just selectively remove a button based on index?
> 
> NB the index for 0 to 2 is just for this example test, in desired 
> application there would be a variable and large number of buttons 
> determined by data and user interaction.
> 
> As a workaround I could do
>      hToolButton = New ToolButton(Me) As "My_Button" & CStr(intIndex)
> which allows me to absolutely delete individual buttons but it means 
> instead of having one
>      Public Sub My_Button_Click()
> I would have to code a large number sub just in case needed, for this 
> example it would just need
>      Public Sub My_Button0_Click()
>      Public Sub My_Button1_Click()
>      Public Sub My_Button2_Click()
> But in the real application I may needs something like potentially 60 of 
> them!
> 
> ALSO
> running the same code in Debian10 KDE does not work the same.
> Clicking btnRemove once removes the last drawn button only (and the 
> first two buttons still work)
> But when click btnRemove again to remove next button it complains 
> Me["My_Button"] is a null object
> K.
> 
> ----[ http://gambaswiki.org/wiki/doc/netiquette ]----
> 

When I needed this, I deleted all objects from last to first with a 
for-next loop step -1.

Like this:

         Inc fldNr
         mTxt.Resize(fldNr + 1)
         mTxt[fldNr] = New TextBox(Maske) As "MaskeFeld"
         mTxt[fldNr].Tag = wert[8] 'fldNr
         mTxt[fldNr].ToolTip = wert[8]
         mTxt[fldNr].X = Val(wert[2])
         mTxt[fldNr].Y = Val(wert[3])


And later this:

   For i = mTxt.Count - 1 To 0 Step -1
     mTxt[i].Delete
   Next
   mTxt.Clear


As long as you point directly to the object, everything runs fine, and I 
included a separate counter (integer variable) to keep control over the 
absolute number of objects. Then delete them one-by-one referencing them 
with this counter.

Regards
Rolf