Embedded forms - accessing procedures on parent forms

Post your Gambas programming questions here.
Post Reply
bazzvn
Posts: 15
Joined: Wednesday 22nd February 2017 11:06am
Location: Vietnam

Embedded forms - accessing procedures on parent forms

Post by bazzvn »

In some of my programs I have been using embedded forms 3 levels deep - i.e. a parent form, a child form on the parent form, and a grandchild form on the child form. For the most part this works well, but I have run into problems trying to execute a procedure on a child form (2nd level) from a grandchild form (3rd level). I'm sure it's possible, but I don't know how to do it. I keep getting an error message (15; Null object). I attach a simple example project with code of what I am trying to do. I would be grateful if somebody could have a quick look at the code and point me in the right direction.

bazzvn
Attachments
Subforms-0.0.1.tar.gz
(12.15 KiB) Downloaded 3 times
User avatar
BruceSteers
Posts: 1042
Joined: Thursday 23rd July 2020 5:20pm
Location: Isle of Wight
Contact:

Re: Embedded forms - accessing procedures on parent forms

Post by BruceSteers »

It's because of this...


Public hChild As FChild

Public Sub Form_Open()
  
 Dim hChild As New FChild(pnlChild)
  
End



Loose the Dim
By using Dim hChild you are making another new hChild variable local to Form_Open() not the public declaration so the
Public hChild As FChild never gets used so it remains to be Null , hence the error message..

try this...

Public hChild As FChild

Public Sub Form_Open()
  
 hChild = New FChild(pnlChild)
  
End



My guess would be you already know all this but that little "Dim" slipped your attention :)
If at first you don't succeed , try something different.
BruceS
Post Reply