Message Box X Button Works like the Cancel Button Of the Box

[Christian Ehrlicher]

Then I would expect a third button for this.

[Bonnie]

@Abhi_Varma

1. Internally QMessageBox will try to find an "escape" button from all buttons to set as the clicked button when "Escape" key is pressed or X is clicked, QMessageBox::RejectRole is one of the case to be chosen.
2. If there is no such button, the X will be disabled.

So if you don't want the discard button and X to act the same, just don't set it's role to QMessageBox::RejectRole.
QMessageBox::DestructiveRole is more suitable for that case.

You can also use StandardButtons like

QMessageBox box;
box.setText("Choose An Option");
box.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel); //I add cancel to make X enabled
box.setDefaultButton(QMessageBox::Save);
int result = box.exec();
if(result == QMessageBox::Save) {
    qInfo() << "Save Button Clicked";
}
else if(result == QMessageBox::Discard) {
    qInfo() << "Discard Button clicked";
}
else
{
    qInfo() << "Cancelled";
}

[Abhi_Varma]

This post is deleted!

[Abhi_Varma]

@Bonnie Okay this looks interesting.... so can I hide the cancel button from the user while making X button stay active

[Bonnie]

@Abhi_Varma
Wow, I would never think of that, but yes you can...
I've tried

box.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel); 
box.button(QMessageBox::Cancel)->hide();

or in your orignal code

QPushButton *pDiscardChangesBtn = box.addButton("Discard Changes", QMessageBox::DestructiveRole);
QPushButton *pSaveChangesBtn = box.addButton("Save Changes", QMessageBox::AcceptRole);
QPushButton *pCancelBtn = box.addButton(QMessageBox::Cancel);
pCancelBtn->hide();

It can do the trick. :)

[Abhi_Varma]

@Bonnie thanks for the quick response.... by the way is it a gud practice to do it this way?

[Bonnie]

@Abhi_Varma
Well, it is not a normal way since Qt intentionally disable X button when there's no escape button.
So this is kind of a cheat way.
Also there's no guarantee that it will always work as expected in all future Qt versions.
I would keep the cancel button if I don't have to hide it.

[Abhi_Varma]

@Bonnie thank you so much :)

[Abhi_Varma]

@Bonnie is there any other way to implement this?

[Bonnie]

@Abhi_Varma
What do you mean? To have the X button enabled without adding and hiding a cancel/close button?
You can, for example, write your own dialog instead of using QMessageBox and handle everything by yourself, but I think there's no need to do that.
I would say hiding the button is already the best solution in my opinion...
If you really need the button invisible, just do it.
I would also cheat / try to change Qt's behavior in my code if I have to.