controls from ui design not showing up when program runs

[qtForumsUser5]

I made a UI design for a QDialog box with a bunch of controls, but when I run it it shows a blank frame, all the controls are missing. I changed the base class of the widget from a QMainWindow to a QDialog after the initial design, maybe it's something to do with that? Any idea why the controls aren't showing up?

[JonB]

@qtForumsUser5 said in controls from ui design not showing up when program runs:

I changed the base class of the widget from a QMainWindow to a QDialog after the initial design, maybe it's something to do with that?

Who knows, maybe, depends what you did.

Your current Object Explorer at the right shows:

• Your top-level QDialog does not have any layout (the "red no-entry" sign). That is wrong.
• It has a child named centralWidget which is also of type QDialog. This is wrong. centralWidget is a QWidget for QMainWindow only, and a QDialog should not have a QDialog as a child.

[CPPUIX]

Hi,

@qtForumsUser5 said in controls from ui design not showing up when program runs:

I changed the base class of the widget from a QMainWindow to a QDialog after the initial design, maybe it's something to do with that?

Yes, exactly, try ui->centralwidget->setVisible(true); in your addSensor ctor, your controls will appear in a separate window, which is a QDialog.

Why did you make a project with QMainWindow, and then changed it to QDialog? And how did you change it?

[JonB]

@qtForumsUser5 said in controls from ui design not showing up when program runs:

I changed the base class of the widget from a QMainWindow to a QDialog after the initial design, maybe it's something to do with that?

Who knows, maybe, depends what you did.

Your current Object Explorer at the right shows:

• Your top-level QDialog does not have any layout (the "red no-entry" sign). That is wrong.
• It has a child named centralWidget which is also of type QDialog. This is wrong. centralWidget is a QWidget for QMainWindow only, and a QDialog should not have a QDialog as a child.

[CPPUIX]

@JonB said in controls from ui design not showing up when program runs:

a QDialog should not have a QDialog as a child.

So that's why ui->centralWidget->setParent(this); did not work when I tried it. Thanks for the clarification.

[qtForumsUser5]

• Your top-level QDialog does not have any layout (the "red no-entry" sign). That is wrong.
• It has a child named centralWidget which is also of type QDialog. This is wrong. centralWidget is a QWidget for QMainWindow only, and a QDialog should not have a QDialog as a child.

Ok, that was the problem. Wasn't aware the mainwindow widget functioned that way, I removed the centralwidget and it works now.

Why did you make a project with QMainWindow, and then changed it to QDialog? And how did you change it?

I made a new project with default settings to quickly prototype a ui design to add to another larger program without realizing I would need to change the base class of the widget. I changed it by editing the XML file <class> </class> tags.

Appreciate the help, cheers.