我無法確定如何更改我的代碼,以便在填寫我的三個文本字段時啓用導航欄中的完成按鈕。只有在所有文本字段已被填寫的情況下才能在Swift中啓用按鈕
我目前有三個UITextFields和一個UIButtonItem。 habitNameField和goalField都是手動文本字段,而frequencyField是拾取器視圖。
@IBOutlet weak var habitNameField: UITextField!
@IBOutlet weak var goalField: UITextField!
@IBOutlet weak var frequencyField: UITextField!
@IBOutlet weak var doneBarButton: UIBarButtonItem!
我還有以下功能,當在第一個字段中輸入某些內容時可以使用。
func textField(habitNameField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let oldHabitNameText: NSString = habitNameField.text!
let newHabitNameText: NSString = oldHabitNameText.stringByReplacingCharactersInRange(range, withString: string)
doneBarButton.enabled = (newHabitNameText.length != 0)
return true
}
我試圖改變代碼,以便它把在其他兩個字段作爲參數,只啓用了doneBarButton如果所有三個領域分別填寫。
func textField(habitNameField: UITextField, goalField: UITextField, frequencyField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let habitNameText: NSString = (habitNameField.text!).stringByReplacingCharactersInRange(range, withString: string)
let goalText: NSString = (goalField.text!).stringByReplacingCharactersInRange(range, withString: string)
let frequencyText: NSString = (frequencyField.text!).stringByReplacingCharactersInRange(range, withString: string)
doneBarButton.enabled = (habitNameText.length != 0) && (goalText.length != 0) && (frequencyText.length != 0)
return true
}
但是,即使我填寫了所有三個文本字段,它仍然無效。
我真的很感謝任何幫助,並感謝所有提前做出貢獻的人!
這裏所有代碼:
class HabitDetailViewController: UITableViewController, UITextFieldDelegate, UIPickerViewDataSource,UIPickerViewDelegate {
@IBOutlet weak var habitNameField: UITextField!
@IBOutlet weak var goalField: UITextField!
@IBOutlet weak var doneBarButton: UIBarButtonItem!
@IBOutlet weak var frequencyField: UITextField!
var frequencies = ["Day", "Week", "Month", "Year"]
var frequencyPicker = UIPickerView()
var habitToEdit: HabitItem?
weak var delegate: HabitDetailViewControllerDelegate?
@IBAction func cancel() {
delegate?.habitDetailViewControllerDidCancel(self)
}
@IBAction func done() {
print("You plan to do \(habitNameField.text!) \(goalField.text!) times a \(frequencyField.text!.lowercaseString).")
if let habit = habitToEdit {
habit.name = habitNameField.text!
habit.numberLeft = Int(goalField.text!)!
habit.frequency = frequencyField.text!
delegate?.habitDetailViewController(self, didFinishEditingHabit: habit)
} else {
let habit = HabitItem()
habit.name = habitNameField.text!
habit.numberLeft = Int(goalField.text!)!
habit.frequency = frequencyField.text!
habit.completed = false
delegate?.habitDetailViewController(self, didFinishAddingHabit: habit)
}
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
habitNameField.becomeFirstResponder()
frequencyPicker.hidden = false
}
override func viewDidLoad() {
super.viewDidLoad()
frequencyPicker.dataSource = self
frequencyPicker.delegate = self
doneBarButton.enabled = false
habitNameField.addTarget(self, action: "checkFields:", forControlEvents: .EditingChanged)
goalField.addTarget(self, action: "checkFields:", forControlEvents: .EditingChanged)
frequencyField.addTarget(self, action: "checkFields:", forControlEvents: .EditingChanged)
frequencyField.inputView = frequencyPicker
if let habit = habitToEdit {
title = "Edit Item"
habitNameField.text = habit.name
goalField.text = String(habit.numberLeft)
doneBarButton.enabled = true
}
}
override func tableView(tableView: UITableView, willSelectRowAtIndexPath indexPath: NSIndexPath) -> NSIndexPath? {
return nil
}
func textField(habitNameField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let oldHabitNameText: NSString = habitNameField.text!
let newHabitNameText: NSString = oldHabitNameText.stringByReplacingCharactersInRange(range, withString: string)
doneBarButton.enabled = (newHabitNameText.length != 0)
return true
}
func checkFields(sender: UITextField) {
sender.text = sender.text?.stringByTrimmingCharactersInSet(.whitespaceCharacterSet())
guard
let habit = habitNameField.text where !habit.isEmpty,
let goal = goalField.text where !goal.isEmpty,
let frequency = frequencyField.text where !frequency.isEmpty
else { return }
// enable your button if all conditions are met
doneBarButton.enabled = true
}
這是行得通的,但由於某些原因,即使只填寫了字段,它也能正常工作。爲什麼? –
Durr。這是我的一個新秀錯誤。感謝您幫助我理解這一點。此外,頻率的最終文本字段不起作用,因爲它是一個選取器視圖。有關於此的任何想法? –
您可以創建一個布爾變量來監視它,並在用戶設置它時將其標記。然後,只需將它添加到警衛聲明 –