Missing Buttons

[PrinzAxel 0]

Has anyone experienced a situation where simple buttons and checklist boxes end up missing on a form when you run your application - for me this is intermittent and I can't determine what conditions are needed to repro the issue.

 

Actually what's strange is that the checklist box is populated but there's no text - but I can click on the items and the border around the item is visible.

 

So far this has only happened on two of our inhouse machines, which are both Dell laptops - there haven't been any reports from customers - the application is 20 years old and I upgraded it from D6 about 8 years ago and have then upgraded through each version up as far as Sydney.

[FPiette 383]

2 hours ago, PrinzAxel said:

for me this is intermittent

Do you mean that for a given application on a give computer, sometimes some buttons and checkboxes (but not all) are missing?

 

Or do you mean that for some application it works and for other it doesn't - always?

 

Is it VCL or FMX application?

 

When you create a simple program, does it happens ?

 

[PrinzAxel 0]

It is a VCL application.

 

Yep I mean for a given application it can work over and over and then without knowing when it can fail.

 

Other controls such as labels, checkboxes and radio buttons appear normally.

 

My next step is to create a new simple program with the same controls and see what happens.

 

Unfortunately the computer that it is happening on is in India and I'm in Ireland.

 

I hope to try remote debugging and maybe use Marco's Object Debugger as well.

 

[Lars Fosdal 1792]

When it fails, does it always fail (on that machine)?

Is there any red thread such as OS version and patch level, display driver, etc between the machines that fail?

[PrinzAxel 0]

This is only the second inhouse machine that has shown the issue.

Both computers are Dell Lattitude 7400s running Windows 20 20H2 and are patched with security and driver updates.

[limelect 48]

@PrinzAxel I do not say that this is your solution but.

When I have crazy staff to debug I copy the project 

and start by taking off staff from the project (compile) until I find

the problem. Yes, I take off components and lines of code.

I know it is hard work but no other choice.

Some time components are hidden under some others.

Look also at your DFM it might help too.

[PrinzAxel 0]

@limelect I appreciate your suggestion and understand where you're coming from.

I don't think it's necessary to take those steps because the application is currently running on thousands of machines without a problem.

So far it is only two machines and as of this morning having tried the most recent machine I cannot get a repro again.

The affected window has not been edited in four years so there haven't been any controls added or moved etc.

I'll keep hunting,

Cheers, Aidan.

[limelect 48]

@PrinzAxel You are correct with your assumption

but if you have the problematic computer under your hand

(Even though the program runs on many computers)

I still go my way. (Unless the computer is far away).

In my long long career with Delphi (since #1) I have seen things you cannot believe.

Well good luck

[Koru 2]

I would look for all the pieces of code that can cause that behavior or touch those components in some way, and leave a log when they are executed making it clear in the log what part of the code has been executed. In the log I would place also information about the new state of the components: position, visible, enabled,...

[limelect 48]

@Koru Do not forget thousand of computers are OK. This way will be too complicated

to execute. I would scrounge my components and source.

But maybe the computers we are talking about are in customer 

location then you have a huge problem of getting customer corporation.

[Koru 2]

It always happens with the same elements of the same form or is it something random along the whole application?

Faced with strange problems of the visual part, I would also check that there is no thread that touches visual things without the correct synchronization

 

[PrinzAxel 0]

@limelect & @Koru I really appreciate your thoughts and comments and I totally agree with your methodologies for breaking down the problem.

Unfortunately the latest/second machine that I was going to troubleshoot this morning is in India and when we looked at it this morning we couldn't get a repro.

I've gone through the code with a fine tooth comb and anywhere that I suspected that could cause problems with the population of the checkbox list would have led to real problems such as AV.

The missing buttons are simply 'OK' and 'Cancel' bit buttons that are not manipulated in any way and just do exactly as titled.

[Lars Fosdal 1792]

When you look in the form designer, are the OK and Cancel buttons correctly parented?

I.e. are they on the expected place in the form hierarchy?

[PrinzAxel 0]

@Lars Fosdal yes the buttons are positioned correctly in the hierarchy.