如何使用NavigationController将数据从UIPickerView传递到以前的ViewController

let navigationController = UINavigationController(rootViewController: yourViewController)

protocol DataDelegate: class {
    func didSelectData(data: String)
}

class PickerViewViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
    weak var delegate: DataDelegate?
    
    // ...
    
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        let selectedData = // 获取选择的数据
        delegate?.didSelectData(data: selectedData)
        navigationController?.popViewController(animated: true)
    }
}

class PreviousViewController: UIViewController, DataDelegate {
    // ...
    
    func didSelectData(data: String) {
        // 在这里处理选择的数据
    }
    
    func navigateToPickerView() {
        let pickerViewVC = PickerViewViewController()
        pickerViewVC.delegate = self
        navigationController?.pushViewController(pickerViewVC, animated: true)
    }
}