使用带有 textFieldShouldReturn 的 Swift 的 Next/Done 按钮

Question

我有一个 MainView，它在按下注册按钮时添加一个子视图 (signUpWindow)。

在我的 signUpWindow 子视图 (SignUpWindowView.swift) 中，我为每个字段设置了一个函数，例如：

func confirmPasswordText()
    {
        confirmPasswordTextField.frame=CGRectMake(50, 210, 410, 50)
        confirmPasswordTextField.placeholder=("Confirm Password")
        confirmPasswordTextField.textColor=textFieldFontColor
        confirmPasswordTextField.secureTextEntry=true
        confirmPasswordTextField.returnKeyType = .Next
        confirmPasswordTextField.clearButtonMode = .WhileEditing
        confirmPasswordTextField.tag=5
        self.addSubview(confirmPasswordTextField)
    }

当 signUpWindow 在 MainView 中出现和消失时，我让键盘上下移动它。

SignUpWindowView 实现 UITextFieldDelegate

我的问题是我正在尝试配置键盘上的下一步/完成按钮，但不确定要添加 textFieldShouldReturn 功能的哪个视图（MainView 或 SignUpWindowView）。我已经尝试了这两种方法，但甚至无法触发println 来测试该函数是否正在执行。一旦我让textFieldShouldReturn 触发，我相信我可以执行必要的代码来让 Next/Done 按钮做我想做的事情，并将发布包含 Next/Done 功能的最终解决方案。

更新为包含 SignUpWindowView.swift 的缩写版本

import UIKit

class SignUpWindowView: UIView,UITextFieldDelegate {

let firstNameTextField:UITextField=UITextField()
let lastNameTextField:UITextField=UITextField()

override func drawRect(rect: CGRect){
    func firstNameText(){
        firstNameTextField.delegate=self
        firstNameTextField.frame=CGRectMake(50, 25, 200, 50)
        firstNameTextField.placeholder="First Name"
        firstNameTextField.returnKeyType = .Next
        self.addSubview(firstNameTextField)
     }

    func lastNameText(){
        lastNameTextField.delegate=self
        lastNameTextField.frame=CGRectMake(260, 25, 200, 50)
        lastNameTextField.placeholder="Last Name"
        lastNameTextField.returnKeyType = .Done
        self.addSubview(lastNameTextField)
     }

    func textFieldShouldReturn(textField: UITextField!) -> Bool{
        println("next button should work")
        if (textField === firstNameTextField)
        {
            firstNameTextField.resignFirstResponder()
            lastNameTextField.becomeFirstResponder()
        }
        return true
     }

    firstNameText()
    lastNameText()
}

Answer 1

您需要在您的类中实现UITextFieldDelegate 并将该对象设置为UITextField 的委托。然后像这样实现方法textFieldShouldReturn:：

func textFieldShouldReturn(textField: UITextField) -> Bool {
    textField.resignFirstResponder()
    if textField == someTextField { // Switch focus to other text field
        otherTextField.becomeFirstResponder()
    }
    return true
}

在您的示例中，您缺少这一行：

confirmPasswordTextField.delegate = self

当然，如果你已经实现了委托。

Answer 2

我试图在 SignUpWindowView.swift 中测试我的文本字段，这是创建所有文本字段的地方。但是，由于我将 SignUpWindowView 作为子视图放入 MainViewController 中，因此我的所有 UITextField“处理”都需要在 MainView 而不是它的子视图中完成。

这是我的 MainViewController 的全部代码（目前），它处理在显示/隐藏键盘时向上/向下移动我的 SignUpWindowView，然后从一个字段移动到下一个字段。当用户位于最后一个文本字段（其键盘 Next 按钮现在在子视图中设置为 Done）时，键盘会收起，然后用户可以使用注册按钮提交表单。

主视图控制器：

import UIKit

@objc protocol ViewControllerDelegate
{
    func keyboardWillShowWithSize(size:CGSize, andDuration duration:NSTimeInterval)
    func keyboardWillHideWithSize(size:CGSize,andDuration duration:NSTimeInterval)
}

class ViewController: UIViewController,UITextFieldDelegate
{
    var keyboardDelegate:ViewControllerDelegate?

    let signUpWindow=SignUpWindowView()
    let signUpWindowPosition:CGPoint=CGPointMake(505, 285)

    override func viewDidLoad()
    {
        super.viewDidLoad()

        // Keyboard Notifications
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)

        // set the textFieldDelegates
        signUpWindow.firstNameTextField.delegate=self
        signUpWindow.lastNameTextField.delegate=self
        signUpWindow.userNameTextField.delegate=self
        signUpWindow.passwordTextField.delegate=self
        signUpWindow.confirmPasswordTextField.delegate=self
        signUpWindow.emailTextField.delegate=self
    }


    func keyboardWillShow(notification: NSNotification)
    {
        var info:NSDictionary = notification.userInfo!
        let keyboardFrame = info[UIKeyboardFrameEndUserInfoKey] as! NSValue
        let keyboardSize = keyboardFrame.CGRectValue().size

        var keyboardHeight:CGFloat = keyboardSize.height

        let animationDurationValue = info[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber

        var animationDuration : NSTimeInterval = animationDurationValue.doubleValue

        self.keyboardDelegate?.keyboardWillShowWithSize(keyboardSize, andDuration: animationDuration)

        // push up the signUpWindow
        UIView.animateWithDuration(animationDuration, delay: 0.25, options: UIViewAnimationOptions.CurveEaseInOut, animations: {
            self.signUpWindow.frame = CGRectMake(self.signUpWindowPosition.x, (self.signUpWindowPosition.y - keyboardHeight+140), self.signUpWindow.bounds.width, self.signUpWindow.bounds.height)
            }, completion: nil)
    }

    func keyboardWillHide(notification: NSNotification)
    {
        var info:NSDictionary = notification.userInfo!

        let keyboardFrame = info[UIKeyboardFrameEndUserInfoKey] as! NSValue
        let keyboardSize = keyboardFrame.CGRectValue().size

        var keyboardHeight:CGFloat = keyboardSize.height

        let animationDurationValue = info[UIKeyboardAnimationDurationUserInfoKey] as! NSNumber

        var animationDuration : NSTimeInterval = animationDurationValue.doubleValue

        self.keyboardDelegate?.keyboardWillHideWithSize(keyboardSize, andDuration: animationDuration)

        // pull signUpWindow back to its original position
        UIView.animateWithDuration(animationDuration, delay: 0.25, options: UIViewAnimationOptions.CurveEaseInOut, animations: {
            self.signUpWindow.frame = CGRectMake(self.signUpWindowPosition.x, self.signUpWindowPosition.y, self.signUpWindow.bounds.width, self.signUpWindow.bounds.height)
            }, completion: nil)
    }

    func textFieldShouldReturn(textField: UITextField) -> Bool
    {
        switch textField
        {
        case signUpWindow.firstNameTextField:
            signUpWindow.lastNameTextField.becomeFirstResponder()
            break
        case signUpWindow.lastNameTextField:
            signUpWindow.userNameTextField.becomeFirstResponder()
            break
        case signUpWindow.userNameTextField:
            signUpWindow.passwordTextField.becomeFirstResponder()
            break
        case signUpWindow.passwordTextField:
            signUpWindow.confirmPasswordTextField.becomeFirstResponder()
            break
        case signUpWindow.confirmPasswordTextField:
            signUpWindow.emailTextField.becomeFirstResponder()
            break
        default:
            textField.resignFirstResponder()
        }
        return true
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    override func viewWillDisappear(animated: Bool) {
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillShowNotification, object: nil)
        NSNotificationCenter.defaultCenter().removeObserver(self, name: UIKeyboardWillHideNotification, object: nil)
    }

    @IBAction func signup()
    {
        signUpWindow.frame=CGRectMake(signUpWindowPosition.x, signUpWindowPosition.y, 485,450)
        signUpWindow.backgroundColor=UIColor.clearColor()

        self.view.addSubview(signUpWindow)
    }
}

Answer 3

使用标签更容易。为您在屏幕上使用的所有文本字段按升序分配标签。

---

func textFieldShouldReturn(_ textField: UITextField) -> Bool {

    let textTag = textField.tag+1
    if let nextResponder = textField.superview?.viewWithTag(textTag) as UIResponder
    {
        //textField.resignFirstResponder()
        nextResponder.becomeFirstResponder()
    }
    else {
        // stop editing on pressing the done button on the last text field.

        self.view.endEditing(true)
    }
    return true
}

Answer 4

您使用@IBAction 连接DidEndOnExit（我是从内存中写的，所以它可能不完全称为但类似）UIControl 事件，并且在该函数中您使用textF.resignFirstResponder() 或.becomeFirstResponder()

---

编辑

UITextField 是 UIControl 的子类，要以编程方式添加新事件，请使用 addTarget() 方法。例如：

func a(sender: AnyObject) {}

textField.addTarget(self, action: "a:", forControlEvents: .EditingDidEndOnExit)

UIControl docs