从qt中的对话框访问主窗口

Question

in the main window their is lineEdit_1 and in the dialog their is lineEdit_2. once a button is clicked the dialog window will open. now I need the lineEdit_2 to get the value of lineEdit_1 in the main window.

(the main window class is MainWindow and dialog window class is dialog )

I tried to do it like this, but it gives a error error: ISO C++ forbids declaration of 'MainWindow' with no type

dialog.h

MainWindow *main; //declair a pointer to the main window

dialog.cpp

lineEdit_2->setText(main->lineEdit_1->text());

whats the mistake here.

I would be very thankful in any advice. thank you.

Answer 1

      void dialog::lineText(QString text){

       lineEdit_text = text;  //let lineEdit_text be a QString member in your 
                              //dialog class. Pass the text before calling
                              //setVisible() in the client code
     }