我想在用户输入时在UITextfield中强制使用小写.
到目前为止我用这段代码出来了,但似乎并没有降低字符.
到目前为止我用这段代码出来了,但似乎并没有降低字符.
func textField(textField: UITextField,shouldChangeCharactersInRange range: NSRange,replacementString string: String) -> Bool {
if string.characters.count == 0 {
return true
}
let currentText = textField.text ?? ""
let prospectiveText = (currentText as NSString).stringByReplacingCharactersInRange(range,withString: string.lowercaseString)
switch textField {
// Allow only lower-case vowels in this field,// and limit its contents to a maximum of 6 characters.
case userNameTextField:
return prospectiveText.characters.count <= 27
default:
return true
}
}
解决方法
首先,您应在文本字段中设置以下属性以限制自动大写：
textfield.autocapitalizationType = UITextAutocapitalizationType.None
这就是你如何进一步限制它：
func textField(textField: UITextField!,replacementString string: String!) -> Bool {
if let _ = string.rangeOfCharacterFromSet(NSCharacterSet.uppercaseLetterCharacterSet()) {
// Do not allow upper case letters
return false
}
return true
}
更新SWIFT 4
func textField(_ textField: UITextField,shouldChangeCharactersIn range: NSRange,replacementString string: String) -> Bool {
if let _ = string.rangeOfCharacter(from: .uppercaseLetters) {
// Do not allow upper case letters
return false
}
return true
}