我正在制作一个游戏，用户必须输入动词的过去时态。我的视图包含只接受一个字符的小文本框。截至目前，当前者包含一个字母时，我正试图自动跳转到下一个文本字段。
我想继续这样做，直到所有的盒子都被填满。用户还应该能够使用键盘上的返回按钮返回一个框。
以下是我目前正在使用的代码，但它没有跳转到下一个文本字段。我做错了什么？
var game: Game? {
didSet {
if var answerContent = game?.answer {
let views = (0..<answerContent.characters.count).map { _ in UITextField(frame: CGRect(x: 0, y: 0, width: 40, height: 40)) }
for textField in views {
textField.backgroundColor = UIColor.white
textField.textColor = Constants.MAIN_THEME_COLOR
textField.textAlignment = NSTextAlignment.center
textField.delegate = self
textField.returnKeyType = .next
textField.tag = views.index(of: textField)! + 1
self.container.addArrangedSubview(textField)
views.first?.becomeFirstResponder()
}
}
}
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let text = textField.text else { return true }
let textLength = text.characters.count + string.characters.count - range.length
return textLength <= 1
}
func textFieldShouldReturn(_ textField: UITextField) -> Bool {
if let nextField = textField.superview?.viewWithTag(textField.tag + 1) as? UITextField {
print("Test")
nextField.becomeFirstResponder()
} else {
print("Test2")
textField.resignFirstResponder()
}
return false
}
更新代码（24-04-2017） - 尝试跳转到下一个textField时返回nil
var game: Game? {
didSet {
if var answerContent = game?.answer {
let views = (0..<answerContent.characters.count).map { _ in UITextField(frame: CGRect(x: 0, y: 0, width: 40, height: 40)) }
for textField in views {
textField.backgroundColor = UIColor.white
textField.textColor = Constants.MAIN_THEME_COLOR
textField.textAlignment = NSTextAlignment.center
textField.delegate = self
textField.addTarget(self, action: #selector(textChanged), for: .editingChanged)
textField.tag = views.index(of: textField)! + 1
self.container.addArrangedSubview(textField)
}
views.first?.becomeFirstResponder()
}
}
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let text = textField.text else { return true }
let textLength = text.characters.count + string.characters.count - range.length
return textLength <= 1
}
func textChanged(sender: UITextField) {
if (sender.text?.characters.count)! > 0 {
print("Entered")
let nextField = textField?.superview?.viewWithTag(textField.tag + 1) as UIResponder!
if (nextField != nil) {
nextField?.becomeFirstResponder()
} else {
print("Error: nil found")
}
} else {
print("Removed")
textField?.resignFirstResponder()
}
}
答案：
var index: NSInteger = 0
for textField in views {
textField.backgroundColor = UIColor.white
textField.textColor = Constants.MAIN_THEME_COLOR
textField.textAlignment = NSTextAlignment.center
textField.autocapitalizationType = UITextAutocapitalizationType.none
textField.delegate = self
textField.addTarget(self, action: #selector(textChanged), for: .editingChanged)
textField.tag = index
self.container.addArrangedSubview(textField)
index+=1
}
func textChanged(sender: UITextField) {
if (sender.text?.characters.count)! > 0 {
let nextField = sender.superview?.viewWithTag(sender.tag + 1) as UIResponder!
nextField?.becomeFirstResponder()
} else {
sender.resignFirstResponder()
}
}
答案 0 :(得分：4)
我建议你应该为控件事件.valueChanged添加一个目标：
// for each text field
textField.addTarget(self, action: #selector(textChanged), for: .valueChanged)
按如下方式实施textChanged：
func textChanged(sender: UITextField) {
if sender.text.characters.length > 0 {
let nextField = textField.superview?.viewWithTag(textField.tag + 1) as? UITextField
nextField?.becomeFistResponder()
}
}
答案 1 :(得分：2)
按照代码：
import UIKit
// used this to set max characters of UITextField in the storyboard
private var __maxLengths = [UITextField: Int]()
extension UITextField {
@IBInspectable var maxLength: Int {
get {
guard let l = __maxLengths[self] else {
return 150 // (global default-limit. or just, Int.max)
}
return l
}
set {
__maxLengths[self] = newValue
addTarget(self, action: #selector(fix), for: .editingChanged)
}
}
func fix(textField: UITextField) {
let t = textField.text
textField.text = t?.safelyLimitedTo(length: maxLength)
}
}
extension String
{
func safelyLimitedTo(length n: Int)->String {
let c = self.characters
if (c.count <= n) { return self }
return String( Array(c).prefix(upTo: n) )
}
}
class ViewController: UIViewController {
@IBOutlet var input1: UITextField!
@IBOutlet var input2: UITextField!
@IBOutlet var input3: UITextField!
@IBOutlet var input4: UITextField!
@IBOutlet var input5: UITextField!
@IBOutlet var input6: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
setup()
// Do any additional setup after loading the view.
}
func setup() {
input1.tag = 1
input2.tag = 2
input3.tag = 3
input4.tag = 4
input5.tag = 5
input6.tag = 6
input1.addTarget(self, action: #selector(textChanged), for: .editingChanged)
input2.addTarget(self, action: #selector(textChanged), for: .editingChanged)
input3.addTarget(self, action: #selector(textChanged), for: .editingChanged)
input4.addTarget(self, action: #selector(textChanged), for: .editingChanged)
input5.addTarget(self, action: #selector(textChanged), for: .editingChanged)
input6.addTarget(self, action: #selector(textChanged), for: .editingChanged)
}
func textChanged(sender: UITextField) {
if (sender.text?.characters.count)! == 1 {
let nextField = sender.superview?.viewWithTag(sender.tag + 1) as UIResponder!
nextField?.becomeFirstResponder()
} else if (sender.text?.characters.count)! == 0 {
let nextField = sender.superview?.viewWithTag(sender.tag - 1) as UIResponder!
nextField?.becomeFirstResponder()
}
}
}
答案 2 :(得分：1)
Swift 4更新
在viewDidLoad()中每个文本字段，
textField.addTarget(self, action: #selector(textChanged), for: .editingChanged)
然后，添加此功能
@objc func textChanged(sender: UITextField) {
if (sender.text?.count)! > 0 {
let nextField = self.view.viewWithTag(sender.tag + 1) as? UITextField
nextField?.becomeFirstResponder()
}
}