How to link a bool variable to a push button in c++ qt?
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@nanor
You seem to be relying on the names of your slots being auto-connected to signals. Put in debug messages to see whether your slots are being called at all? -
@JonB Thank you for replying. I don't understand exactly what to do. Do you mean I must run the code in debugging mode and see if there are errors or not?
I ran the code in debugging mode and there were no errors.@nanor
Put lines likeqDebug() << "Got to this line (1)"(you may need#include <QDebug>at the top of your file) into youron_pushButton_clicked()&on_pushButton_2_clicked()slots. When you run from Qt Creator, do you see output appearing (I think it's in the "Application Output" tab at the bottom)? -
@nanor
Put lines likeqDebug() << "Got to this line (1)"(you may need#include <QDebug>at the top of your file) into youron_pushButton_clicked()&on_pushButton_2_clicked()slots. When you run from Qt Creator, do you see output appearing (I think it's in the "Application Output" tab at the bottom)?@JonB I put qDebug() << "1" into on_pushButton_clicked() and qDebug() << "2"; into on_pushButton_2_clicked() . I see outputs when I run the code.
The code works well (after clicking on the pushButton , the labels become unhide and after clicking the pushButton_2(which is related to the multiply of two numbers) it works well too).
The only part that does not work, is when I click on the pushButton for the second time to hide the labels again(When I click on the pushButton for the second time, all the labels remain, but my goal is to hide them again, but nothing happens). -
@JonB I put qDebug() << "1" into on_pushButton_clicked() and qDebug() << "2"; into on_pushButton_2_clicked() . I see outputs when I run the code.
The code works well (after clicking on the pushButton , the labels become unhide and after clicking the pushButton_2(which is related to the multiply of two numbers) it works well too).
The only part that does not work, is when I click on the pushButton for the second time to hide the labels again(When I click on the pushButton for the second time, all the labels remain, but my goal is to hide them again, but nothing happens).@nanor said in How to link a bool variable to a push button in c++ qt?:
When I click on the pushButton for the second time, all the labels remain, but my goal is to hide them again, but nothing happen
So look at your code in
on_pushButton_clicked()where you callsetVisible(true)on each widget. So why do you expect them to disappear? What could you write there instead oftruethere to make it work as you want? -
@nanor said in How to link a bool variable to a push button in c++ qt?:
When I click on the pushButton for the second time, all the labels remain, but my goal is to hide them again, but nothing happen
So look at your code in
on_pushButton_clicked()where you callsetVisible(true)on each widget. So why do you expect them to disappear? What could you write there instead oftruethere to make it work as you want?@JonB Yes, that's right. But I wrote bForButton = !bForButton; before writing the setvisible(true) for the items in on_pushbutton_clicked(). As in the constructor I wrote bForButton = false, I thought that for the second time clicking on the pushbutton, the boolian value turns into false again and all of the elements become hide again.
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@JonB Yes, that's right. But I wrote bForButton = !bForButton; before writing the setvisible(true) for the items in on_pushbutton_clicked(). As in the constructor I wrote bForButton = false, I thought that for the second time clicking on the pushbutton, the boolian value turns into false again and all of the elements become hide again.
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@JonB Yes, that's right. But I wrote bForButton = !bForButton; before writing the setvisible(true) for the items in on_pushbutton_clicked(). As in the constructor I wrote bForButton = false, I thought that for the second time clicking on the pushbutton, the boolian value turns into false again and all of the elements become hide again.
@nanor said in How to link a bool variable to a push button in c++ qt?:
But I wrote bForButton = !bForButton
Think about how/why that then messes things up from then on, because you have changed the value of the
bForButtonvalue in doing so. You must not change that variable itself. Hint: it's OK to pass!bForButtonas an expression/parameter, but not to gobForButton = !bForButton.... Or, you could choose to go down @Bob64's "current widget visibility" route, though that's more code to write/maintain. -
@nanor but what is using
bForButton?Actually it is better not to use this flag at all. Can you query the button's current visibility?
@Bob64 Actually I used bForButton to hide and unhide the labels by clicking on push buttons (For the first time clicking on the push_button, I want to unhide the labels, for the second time clicking on the push_button I want to hide them again, for the third time the goal is unhiding them again...).
I set bForButton=false for hiding and bForButton=!bForButton for unhiding them. -
@nanor said in How to link a bool variable to a push button in c++ qt?:
But I wrote bForButton = !bForButton
Think about how/why that then messes things up from then on, because you have changed the value of the
bForButtonvalue in doing so. You must not change that variable itself. Hint: it's OK to pass!bForButtonas an expression/parameter, but not to gobForButton = !bForButton.... Or, you could choose to go down @Bob64's "current widget visibility" route, though that's more code to write/maintain. -
@JonB I put setVisible(bForButton) instead of setVisible(true) for the elements into on_pushButton_clicked() slots and my code worked well. Thank you so much. I really appreciate your help.
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@JonB I put setVisible(bForButton) instead of setVisible(true) for the elements into on_pushButton_clicked() slots and my code worked well. Thank you so much. I really appreciate your help.
@nanor said in How to link a bool variable to a push button in c++ qt?:
my code worked well
great, so please don't forget to mark your post as solved!
