Rx swift - Date picker freezes Rx swift View controller - ios

Question

Here is code i am using, i am new to rxswift. My question is simple when i tap on textfield date picker opens and it freezes my ViewController. I don't know what is the problem with UI in rxswift, this works well in only swift project. Your help is appreaciated pls help.
class ViewController: UIViewController {
//Text Field Connection
#IBOutlet weak var txtDatePicker: UITextField!
//Uidate picker
let datePicker = UIDatePicker()
override func viewDidLoad() {
super.viewDidLoad()
//show date picker
showDatePicker()
}
func showDatePicker(){
//Formate Date
datePicker.datePickerMode = .date
//ToolBar
let toolbar = UIToolbar();
toolbar.sizeToFit()
//done button & cancel button
let doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.bordered, target: self, action: "donedatePicker")
let spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
let cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.bordered, target: self, action: "cancelDatePicker")
toolbar.setItems([doneButton,spaceButton,cancelButton], animated: false)
// add toolbar to textField
txtDatePicker.inputAccessoryView = toolbar
// add datepicker to textField
txtDatePicker.inputView = datePicker
}
func donedatePicker(){
//For date formate
let formatter = DateFormatter()
formatter.dateFormat = "dd/MM/yyyy"
txtDatePicker.text = formatter.string(from: datePicker.date)
//dismiss date picker dialog
self.view.endEditing(true)
}
func cancelDatePicker(){
//cancel button dismiss datepicker dialog
self.view.endEditing(true)
}
}
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