Form QLineEdit

[waynew]

Simple situation, but I can't find an answer.
Can anyone please point me to an example of how to setText() of a lineEdit field in a form from a different class? How to reference the form?
I tried this in the other class cpp:

Ui_Form *form;
form -> lineEditField -> setText("ABC");

Ui_Form *form;
form -> lineEditField -> setText("ABC");

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Crashes the application