［背景］
需要对于文本框来说，超过11位之后，就不允许继续输入了
搜：
swift textfield input change
swift textfield input change not allow
ios – Allow only Numbers for UITextField input – Stack Overflow
但是：
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool { let allow = true if let inputText = textField.text { let updatedStr:String = inputText.stringByReplacingCharactersInRange(range, withString: string) print("updatedStr=\(updatedStr)") } return allow } |
却出错：
Cannot convert value of type ‘NSRange’ (aka ‘_NSRange’) to expected argument type ‘Range<Index>’ (aka ‘Range<String.CharacterView.Index>’) |
去搜：
swift textfield shouldChangeCharactersInRange
ios – How shouldChangeCharactersInRange works in Swift? – Stack Overflow
ios – Textfield shouldchangecharactersinrange swift – Stack Overflow
ios – UITextView shouldChangeCharactersInRange in Swift – Stack Overflow
最后用代码：
class RegisterPhoneViewController: UIViewController, UITextFieldDelegate { phoneTextField.delegate = self functextField(textField:UITextField, shouldChangeCharactersInRange range:NSRange, replacementString string:String) ->Bool{ var allow = true print("range=\(range), string=\(string)") if let inputText = textField.text { let updatedStr:String = (inputText as NSString).stringByReplacingCharactersInRange(range, withString: string) print("updatedStr=\(updatedStr)") if updatedStr.characters.count > 11 { allow = false } } return allow } |
实现了效果：
一直输入，直到输入了11位数字，再多就不允许输入了：
range=(0,0), string=1 updatedStr=1 range=(1,0), string=3 updatedStr=13 range=(2,0), string=8 updatedStr=138 range=(3,0), string=1 updatedStr=1381 range=(4,0), string=2 updatedStr=13812 range=(5,0), string=3 updatedStr=138123 range=(6,0), string=4 updatedStr=1381234 range=(7,0), string=5 updatedStr=13812345 range=(8,0), string=6 updatedStr=138123456 range=(9,0), string=7 updatedStr=1381234567 range=(10,0), string=8 updatedStr=13812345678 range=(11,0), string=0 updatedStr=138123456780 range=(11,0), string=0 updatedStr=138123456780 |
如图：
转载请注明：在路上 » ［已解决］swift中动态判断文本框输入的内容决定是否允许输入