[英]Auto switching between UITextFields with Swift
我在一个UIView
有4个UITextFields
,如下所示:
每个UITextField
限制为4个字符。 我想实现之间的自动切换UITextFields
与每个数字符UITextField
。
我使用shouldChangeCharactersIn
作为限制字符:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let maxLength = 4
var newString = String()
let currentString: NSString = textField.text! as NSString
newString = currentString.replacingCharacters(in: range, with: string)
return newString.length <= maxLength
}
这是我的切换工具:
func textFieldDidChange(_ textField: UITextField){
let text = textField.text
if text?.utf16.count == 4 {
switch textField {
case firstPartTextField:
secondPartTextField.becomeFirstResponder()
case secondPartTextField:
thirdPartTextField.becomeFirstResponder()
case thirdPartTextField:
fourthPartTextField.becomeFirstResponder()
default:
break
}
}
}
我的问题是在删除文本时切换到以前的UITextField
,当UITextField
为空时我无法检测到BackSpace事件。
在viewDidLoad()中为textField添加目标
firstTxt.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: UIControlEvents.editingChanged)
secTxt.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: UIControlEvents.editingChanged)
thirdTxt.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: UIControlEvents.editingChanged)
fourTXt.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: UIControlEvents.editingChanged)
比创建选择器方法
func textFieldDidChange(textField:UITextField){
let text = textField.text
if text?.utf16.count == 1{
switch textField{
case firstTxt:
secTxt.becomeFirstResponder()
case secTxt:
thirdTxt.becomeFirstResponder()
case thirdTxt:
fourTXt.becomeFirstResponder()
case fourTXt:
fourTXt.resignFirstResponder()
default:
break
}
}else{
}
}
收集所有文本字段的出口,并按如下方式配置它们:
OutletCollection: @IBOutlet var textfields: [UITextField]!
将此添加到viewDidLoad中:
func textFieldDidBeginEditing(_ textField: UITextField) {
textField.text = ""
}
在目标函数中,将以这种方式限制计数:
func textFieldDidChange(textField: UITextField) { let text = textField.text! if text.utf16.count >= 4 { if textField.tag < 4 { codeTextfields[textField.tag + 1].becomeFirstResponder() } else { textField.resignFirstResponder() } } }
这将改变您的委托方法之一:
func textFieldDidBeginEditing(_ textField: UITextField) { textField.text = "" }
精炼版本的答案如下: 如何在ios中以编程方式自动将光标从一个文本字段移动到另一个文本字段?
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