Program failing at Run time
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Hi All,
Just starting with Qt and really going through a few tutorials and reading a few books trying to get my skill levels up. Really enjoying it at the moment.
I hit a problem on an example program that I am failing to resolve...
This is an exercise from a book i am reading. Instead of just downloading the source code for the problem I'm actually writing the program as I go along. I already had to correct some issues on it to do with the windows api access, but now all seems good and builds fine but when I run it, it crashes immediately.
I have now downloaded the source code from their website, corrected the same issues with the api and their program works fine. I then compared their files with mine and I can see any significant differences between them so I am at a loss here.
This is my program files:The problem is with QLayout as far as I can see it, but I can't really see why. If I include QLayout on mainwindow.cpp, it will build fine but will crash on run time.
I am re-writing the program from scratch but would really like to know what the problem is, as it is driving me up the wall! I would be grateful for some advice.
Thank you.
Best Regards
Luis -
Hi All,
Just starting with Qt and really going through a few tutorials and reading a few books trying to get my skill levels up. Really enjoying it at the moment.
I hit a problem on an example program that I am failing to resolve...
This is an exercise from a book i am reading. Instead of just downloading the source code for the problem I'm actually writing the program as I go along. I already had to correct some issues on it to do with the windows api access, but now all seems good and builds fine but when I run it, it crashes immediately.
I have now downloaded the source code from their website, corrected the same issues with the api and their program works fine. I then compared their files with mine and I can see any significant differences between them so I am at a loss here.
This is my program files:The problem is with QLayout as far as I can see it, but I can't really see why. If I include QLayout on mainwindow.cpp, it will build fine but will crash on run time.
I am re-writing the program from scratch but would really like to know what the problem is, as it is driving me up the wall! I would be grateful for some advice.
Thank you.
Best Regards
Luis@Luism
Hi
I dont have any QtCharts so could not run code.However, i saw u are using a standalone layout and your issues might come from that.
Please read docs on how to use them
http://doc.qt.io/qt-5/designer-layouts.htmlAdding layouts are done by right clicking. very rarely by dragging from widget collection.
Its other type of use case.
So i think you crash here ( mainwindow constructor)
ui->centralWidget->layout()->
As centralWidget DO NOT have a layout and it return NULL.
Check that :)
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Hi,
I am definitely missing something here... If I try to insert a layout by right clicking I don't get the same menu as you, the layouts are all greyed out.I did manage to make it work by dragging a Vertical Layout from the widget collection and then replace
ui->centralWidget->layout()->addWidget(&mCpuWidget);
with
ui->verticalLayout->addWidget(&mCpuWidget);
Is this a way it should be done?
Thank you for your help.
Best Regards
Luis -
Hi,
I am definitely missing something here... If I try to insert a layout by right clicking I don't get the same menu as you, the layouts are all greyed out.I did manage to make it work by dragging a Vertical Layout from the widget collection and then replace
ui->centralWidget->layout()->addWidget(&mCpuWidget);
with
ui->verticalLayout->addWidget(&mCpuWidget);
Is this a way it should be done?
Thank you for your help.
Best Regards
Luis-i f I try to insert a layout by right clicking I don't get the same menu as you, the layouts are all greyed out.
You must first place a widget (any) , then its not grey any more. :)
Yes, its a bit tricky. :(
ui->verticalLayout->addWidget(&mCpuWidget);
Is not what you want., its a floating layout :)
The right click is the way in most cases.
