Show UIPickerView like a keyboard, without UITextField

Question

I\'m looking for a way to present a UIPickerView when the user taps on a UIBarButtonItem. Imagine a filter for the table view results.

I know I

Answer 1

The cleanest way at least for me, and for Swift4 + Autolayout solution, without a UITextField is adding a UIView as a container of the UIPickerView and a UIToolbar for the top views/buttons.

Then toggle the inset/offset of that container view with animation if you want, to hide and unhide the picker.

PROPERTIES

private lazy var view_PickerContainer: UIView = {
    let view = UIView()
    view.backgroundColor = .white
    view.addSubview(self.timePicker)
    view.addSubview(self.toolbar_Picker)
    return view
}()

private lazy var timePicker: UIDatePicker = {
    let picker = UIDatePicker()
    picker.minimumDate = Date()
    picker.datePickerMode = .time
    picker.setDate(Date(), animated: true)
    return picker
}()

private let timeFormatter: DateFormatter = {
    let formatter = DateFormatter()
    formatter.dateFormat = "hh:mm a"
    return formatter
}()

private lazy var toolbar_Picker: UIToolbar = {
    let toolbar = UIToolbar()
    toolbar.barStyle = .blackTranslucent
    toolbar.barTintColor = .blueDarkText
    toolbar.tintColor = .white
    self.embedButtons(toolbar)
    return toolbar
}()

I use SnapKit to layout my views programmatically. You can use the timePicker's bounds.size as reference for your layout.

IMPLEMENTATION

In viewDidLoad()

    // Setup timepicker and its container.
    self.view.addSubview(self.view_PickerContainer)
    self.view_PickerContainer.snp.makeConstraints { (make) in
        make.height.equalTo(self.timePicker.bounds.size.height + 50.0)
        make.leading.trailing.equalToSuperview()
        self.constraint_PickerContainerBottom = make.bottom.equalToSuperview().inset(-500.0).constraint
    }

    self.timePicker.snp.makeConstraints { (make) in
        make.height.equalTo(self.timePicker.bounds.size.height)
        make.width.equalToSuperview()
        make.bottom.equalToSuperview()
    }

    // Add toolbar for buttons.
    self.toolbar_Picker.snp.makeConstraints { (make) in
        make.height.equalTo(40.0)
        make.top.leading.trailing.equalToSuperview()
    }

Embedding top views

private func embedButtons(_ toolbar: UIToolbar) {
    func setupLabelBarButtonItem() -> UIBarButtonItem {
        let label = UILabel()
        label.text = "Set Alarm Time"
        label.textColor = .white
        return UIBarButtonItem(customView: label)
    }

    let todayButton = UIBarButtonItem(title: "Today", style: .plain, target: self, action: #selector(self.todayPressed(_:)))

    let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(self.donePressed(_:)))

    let flexButton = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: self, action: nil)

    toolbar.setItems([todayButton, flexButton, setupLabelBarButtonItem(), flexButton, doneButton], animated: true)
}

And the result looks like this: