Ui::MainWindow *ui; Could it work without use the prefix?

[grafenocarbono]

Hi Geeks,

I have defined the following code:
...................
;..................
namespace Ui {
class MainWindow;
}
..................
.................
Ui::MainWindow *ui;
.....................
.....................

Why do I have to use the prefix "Ui" of namespace in the sentence "Ui::MainWindow *ui;"?. Could it work without use the prefix?

Thanks in advance

[Chris Kawa]

@grafenocarbono Project template generates structure like this:

namespace Ui {
    class MainWindow;
}

class MainWindow : public QMainWindow
{
    ...
    Ui::MainWindow *ui;
}

MainWindow and Ui::MainWindow are two different classes. Ui::MainWindow is the class generated from the .ui file. If you remove the namespace from Ui::MainWindow *ui; you'll get a pointer to self, and that doesn't make sense.

If you don't want the namespace you can also use the version without it:

class Ui_MainWindow;

class MainWindow : public QMainWindow
{
    ...
    Ui_MainWindow *ui;
}

or rename the widget in the designer to e.g. MyClass and then

class Ui_MyClass;

class MainWindow : public QMainWindow
{
    ...
    Ui_MyClass *ui;
}

or the namespace version.

[JonB]

@Chris-Kawa said in Ui::MainWindow *ui; Could it work without use the prefix?:

MainWindow and Ui::MainWindow are two different classes

@grafenocarbono
As @Chris-Kawa has written, this is a vital observation to get your head around. Designer produces code where all the UI stuff goes into a Ui::MainWindow class and gives you a separate MainWindow class where you write whatever code of your own which can access the widgets in Ui::MainWindow class without stuff there interfering with whatever you declare in your MainWindow class.