Program crashes when trying to change label text from another class.

[johnAdams]

Hi,

I'm building a simple program, where a push button is clicked, it changes text of label, but the thing is, the program works fine when I write code in MainWindow.cpp , i.e the file where code is autogenerated for ui. But, the program crashes, when I try to call a function from another class, and try to change text from that class.

The following way works.

MainWindow.cpp

void MainWindow::on_pushButton_1_clicked()
{
   ui->stackedWidget->setCurrentIndex(1);
   ui->myLabel->setText("This works!");
}

But, when I try to call a function and try to manipulate the label from inside of that function, the program crashes.

The following way doesn't work.

void MainWindow::on_pushButton_1_clicked()
{
    ui->stackedWidget->setCurrentIndex(1);
    gamePlay *play= new gamePlay();
    play.playGame();
}

Inside another class.

void gamePlay::playGame() {
    
   ui->myLabel->setText("This does not work!");
}

The program doesn't crash when I try to call the empty function, but when I try to change text of label, it crashes.

I have included all MainWindow header files in gamePlay header files, but it still doesn't work. What am I missing? Please let me know.

[jsulm]

@johnAdams said in Program crashes when trying to change label text from another class.:

but when I try to change text of label, it crashes.

Was ui initialised in gamePlay?