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QLineedit's text() isnt working
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Why isnt working text() in this program?
https://pastebin.com/WQrqLVG9 -
In the location you are calling QLineEdit::text(), i.e. the constructor, the line edits will all contain nothing because they start that way and have not yet been presented to the user. Converting a blank string to an integer probably gives zero (and a fail code that you are not checking).
If you want to do something with the user input, for example when they push the OK button, then this should happen in a slot, not the constructor.
Also, the logic you are using for the date "difference" is not going to work in the general case.