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exec vs open in QDialogs
When working with QDialogs in Qt, you may come across two different methods: exec and open. These methods are used to display the dialog to the user and handle the user interaction, but they have some key differences that you should be aware of.
exec
The exec method is a blocking call that displays the dialog and waits for the user to interact with it. This means that the code execution is paused until the user closes the dialog, and the method returns an integer value representing the user’s interaction (e.g. QDialog::Accepted or QDialog::Rejected).
For example, if you want to display a QDialog and wait for the user to press a button before continuing with the rest of your code, you can use the exec method like this:
“`cpp
MyDialog dialog;
if(dialog.exec() == QDialog::Accepted) {
// user accepted the dialog
// do something…
}
“`
open
The open method, on the other hand, is a non-blocking call that displays the dialog and returns immediately, allowing your code to continue running in parallel with the dialog being displayed to the user. This is useful if you want to keep your UI responsive and handle user interaction asynchronously.
Here’s an example of how you can use the open method to display a QDialog:
“`cpp
MyDialog dialog;
dialog.open();
// continue with the rest of your code…
“`
Which one to use?
So, which method should you use when working with QDialogs? It depends on your specific requirements. If you need to wait for the user to interact with the dialog and make a decision that affects the rest of your code, then exec is the way to go. On the other hand, if you want to display the dialog and continue running your code in parallel, then open is the better choice.
Ultimately, the decision of whether to use exec or open will depend on your specific use case and what behavior you want to achieve in your application.
Thanks for this information.
good stuff