How to use LLDB (XCode) to change the view background color at runtime and update view UI on the simulator

Question

I have this code:

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        // Line where the breakpoint will be placed
        view.backgroundColor = UIColor.green
    }
}

I want to add breakpoint, execute the app on the simulator, and when the execution is paused, I want to use the LLDB to change backgroundColor to blue and see the background on the simulator on blue color.

How to do that?

Answer 1

I found this solution:

• Set a breakpoint in the same line that you want do change/update in runtime
• Run the app on the simulator. When the execution is paused, type this expression on the main thread in the XCode console:

e DispatchQueue.main.async { self.view.backgroundColor = UIColor.blue }

• Hit Enter and release the execution. You will see the background changing from green to blue on the simulator.

This is a good UI solution for UIkit projects without SwiftUI #Preview{}