我希望用户只在UITextField 中输入数值。在 iPhone 上我们可以显示数字键盘，但在 iPad 上用户可以切换到任何键盘。
有没有办法限制用户在UITextField 中只输入数值？
【问题讨论】：
标签： ios iphone swift ipad uitextfield
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let allowedCharacters = CharacterSet.decimalDigits
let characterSet = CharacterSet(charactersIn: string)
return allowedCharacters.isSuperset(of: characterSet)
}
【讨论】：
UITextFieldDelegate，在viewDidLoad中放入yourNumbersTextField.delegate = self
这是我的 2 美分。 （仅在 Swift 2 上测试）
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let aSet = NSCharacterSet(charactersInString:"0123456789").invertedSet
let compSepByCharInSet = string.componentsSeparatedByCharactersInSet(aSet)
let numberFiltered = compSepByCharInSet.joinWithSeparator("")
return string == numberFiltered
}
这只是更严格一点。也没有小数点。
希望对你有帮助:)
PS：我还以为你照顾了委托人。
更新：Swift 3.0：
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let aSet = NSCharacterSet(charactersIn:"0123456789").inverted
let compSepByCharInSet = string.components(separatedBy: aSet)
let numberFiltered = compSepByCharInSet.joined(separator: "")
return string == numberFiltered
}
【讨论】：
aSet 设置为CharacterSet.decimalDigits.invertedSet
text == "" 的检查，以便用户可以向后删除文本。
在 swift 4.1 和 Xcode 9.4.1 中
将 UITextFieldDelegate 添加到您的班级
class YourViewController: UIViewController, UITextFieldDelegate
然后在你的 viewDidLoad()
中编写这段代码mobileNoTF.delegate = self
编写此文本字段委托函数
//MARK - UITextField Delegates
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
//For mobile numer validation
if textField == mobileNoTF {
let allowedCharacters = CharacterSet(charactersIn:"+0123456789 ")//Here change this characters based on your requirement
let characterSet = CharacterSet(charactersIn: string)
return allowedCharacters.isSuperset(of: characterSet)
}
return true
}
【讨论】：
Binary operator '==' cannot be applied to operands of type 'UITextField' and '() -> ()'
斯威夫特 2.0
只允许数字和一个“。” uitextfield 中的小数。
func textField(textField: UITextField,shouldChangeCharactersInRange range: NSRange,replacementString string: String) -> Bool
{
let newCharacters = NSCharacterSet(charactersInString: string)
let boolIsNumber = NSCharacterSet.decimalDigitCharacterSet().isSupersetOfSet(newCharacters)
if boolIsNumber == true {
return true
} else {
if string == "." {
let countdots = textField.text!.componentsSeparatedByString(".").count - 1
if countdots == 0 {
return true
} else {
if countdots > 0 && string == "." {
return false
} else {
return true
}
}
} else {
return false
}
}
}
【讨论】：
【讨论】：
在 Swift 3 中接受带有单个 (.) 点的文本字段中的十进制值
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let inverseSet = NSCharacterSet(charactersIn:"0123456789").inverted
let components = string.components(separatedBy: inverseSet)
let filtered = components.joined(separator: "")
if filtered == string {
return true
} else {
if string == "." {
let countdots = textField.text!.components(separatedBy:".").count - 1
if countdots == 0 {
return true
}else{
if countdots > 0 && string == "." {
return false
} else {
return true
}
}
}else{
return false
}
}
}
【讨论】：
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
// return true if the replacementString only contains numeric characters
let digits = NSCharacterSet.decimalDigitCharacterSet()
for c in string {
if !digits.characterIsMember(c) {
return false
}
}
return true
}
即使用户切换键盘或尝试将非数字字符串粘贴到文本字段中，此解决方案也可以工作。
确保设置相应文本字段的delegate 属性。
【讨论】：
[string intValue] 如上一个答案中所建议的将不起作用，因为即使string 包含非数字字符，该属性也可能为真（非零）。根据文档，intValue 仅在“字符串不以数字的有效十进制文本表示开头”时为 0。
使用数字格式化程序
Swift 4.x
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let s = NSString(string: textField.text ?? "").replacingCharacters(in: range, with: string)
guard !s.isEmpty else { return true }
let numberFormatter = NumberFormatter()
numberFormatter.numberStyle = .none
return numberFormatter.number(from: s)?.intValue != nil
}
【讨论】：
这是一个简单的解决方案，您需要在控制器中将“编辑更改”事件连接到此方法
斯威夫特 4
@IBAction func valueChanged(_ sender: UITextField) {
if let last = sender.text?.last {
let zero: Character = "0"
let num: Int = Int(UnicodeScalar(String(last))!.value - UnicodeScalar(String(zero))!.value)
if (num < 0 || num > 9) {
//remove the last character as it is invalid
sender.text?.removeLast()
}
}
}
【讨论】：
像这样扩展你的视图控制器：
class MyViewController: UIViewController, UITextFieldDelegate
在 viewDidLoad 函数中，像这样扩展到您的文本字段：
myTextField.delegate = self
然后使用下面的函数：
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let isNumber = CharacterSet.decimalDigits.isSuperset(of: CharacterSet(charactersIn: string))
let withDecimal = (
string == NumberFormatter().decimalSeparator &&
textField.text?.contains(string) == false
)
return isNumber || withDecimal
}
这将确保用户只能输入十进制数字。
斯威夫特 4 + 只接受号码 并接受一个分隔符
【讨论】：
第一个你必须继承你自己的 UITextFieldDelegate 类 类
class ViewController: UIViewController, UITextFieldDelegate {
第二次添加 IBOutlet
@IBOutlet weak var firstName: UITextField!
第三你必须确保这个对象正在使用
override func viewDidLoad() {
super.viewDidLoad()
firstName.delegate = self
}
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
if textField == firstName {
let allowedCharacters = "1234567890"
let allowedCharacterSet = CharacterSet(charactersIn: allowedCharacters)
let typedCharacterSet = CharacterSet(charactersIn: string)
let alphabet = allowedCharacterSet.isSuperset(of: typedCharacterSet)
return alphabet
}
}
【讨论】：
//除了这些，您只需将键盘更改为数字类型
yourtextfield.keyboardType = UIKeyboardType.numberPad
【讨论】：
虽然这些解决方案中的大多数都可以使用，但请注意，在某些本地化版本中，小数用“，”而不是“。”分隔。
更简洁的方法是
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let decimalCharacter = NSNumberFormatter().decimalSeparator
let characterSet = NSMutableCharacterSet.decimalDigitCharacterSet()
characterSet.addCharactersInString(decimalCharacter)
return replacementString.rangeOfCharacterFromSet(characterSet.invertedSet) == nil
}
【讨论】：
在 swift 3.0 中测试
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool
{
let numberOnly = NSCharacterSet.init(charactersIn: "0123456789")
let stringFromTextField = NSCharacterSet.init(charactersIn: string)
let strValid = numberOnly.isSuperset(of: stringFromTextField as CharacterSet)
return strValid
}
【讨论】：
这是一个更清洁的解决方案：
guard CharacterSet(charactersIn: "123456789").isSuperset(of: CharacterSet(charactersIn: string)) else {
return false
}
return true
对于小数只需添加.，例如123456789.
【讨论】：
设置 KeyboardType 属性：- 数字键盘 TextField Delegate 请写下代码
func textField(_ textField: UITextField, shouldChangeCharactersIn
range: NSRange, replacementString string: String) -> Bool {
if textField.text?.count == 0 && string == "0" {
return false
}
return string == string.filter("0123456789".contains)
}
数字不能从0开始，输入数字+ve。
【讨论】：
我在阅读 Big Nerd Ranch 书时实际上已经这样做了，我的解决方案是：
func textField(textField: UITextField,
shouldChangeCharactersInRange range: NSRange,
replacementString string: String) -> Bool {
let newCharacters = NSCharacterSet(charactersInString: string)
return NSCharacterSet.decimalDigitCharacterSet().isSupersetOfSet(newCharacters)
}
这只允许数字0-9，允许“。”也更复杂，因为您只能允许一个“。”
【讨论】：
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
if let numRange = string.rangeOfCharacterFromSet(NSCharacterSet.letterCharacterSet()) {
return false
} else {
return true
}
}
【讨论】：
要只允许数字和一个小数运算符，您可以使用以下解决方案：
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let isNumber = NSCharacterSet.decimalDigitCharacterSet().isSupersetOfSet(NSCharacterSet(charactersInString: string))
return isNumber || (string == NSNumberFormatter().decimalSeparator && textField.text?.containsString(string) == false)
}
【讨论】：
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool
{
let textString = (textField.text! as NSString).replacingCharacters(in: range, with: string)
if textField == self.phoneTextField && string.characters.count > 0{
let numberOnly = NSCharacterSet.decimalDigits
let strValid = numberOnly.contains(UnicodeScalar.init(string)!)
return strValid && textString.characters.count <= 10
}
return true
}
上面的代码在 swift 3 中工作
NSCharacterSet.decimalDigits
您也只能使用字母
NSCharacterSet.字母
和大写、小写和、字母数字、空格
使用相同的代码
或See the Link
【讨论】：
我认为你可以通过实现 UITextInputTraits 协议，可选的 var keyboardType 来强制改变键盘类型
//class ViewController: UIViewController, UITextInputTraits {
@IBOutlet weak var textFieldKeyboardType: UITextField!{
didSet{
textFieldKeyboardType.keyboardType = UIKeyboardType.NumberPad
}
}
var keyboardType: UIKeyboardType {
get{
return textFieldKeyboardType.keyboardType
}
set{
if newValue != UIKeyboardType.NumberPad{
self.keyboardType = UIKeyboardType.NumberPad
}
}
}
【讨论】：
这是一个可读性更强的版本，将“0-9”加上“.”：
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let existingTextHasDecimal = textField.text?.rangeOfString(".")
let replacementTextHasDecimal = string.rangeOfString(".")
let replacementTextAllCharacters = NSCharacterSet(charactersInString: string)
let replacementTextOnlyDigits = NSCharacterSet.decimalDigitCharacterSet().isSupersetOfSet(replacementTextAllCharacters)
if replacementTextHasDecimal != nil && existingTextHasDecimal != nil {
return false
}else{
if replacementTextOnlyDigits == true {
return true
}else if replacementTextHasDecimal != nil{
return true
}else{
return false
}
}
}
【讨论】：
好像没有足够的答案，这是我的。我认为允许使用小数分隔符的每个示例在本地化、退格或复制/粘贴方面都有缺陷。
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
if string.isEmpty {return true} //allow for backspace
let decimalSeparator = NSNumberFormatter().decimalSeparator ?? "."
let validChars = NSMutableCharacterSet(charactersInString: decimalSeparator)
validChars.formUnionWithCharacterSet(NSCharacterSet.decimalDigitCharacterSet())
if validChars.isSupersetOfSet(NSCharacterSet(charactersInString: string)){
switch string.componentsSeparatedByString(decimalSeparator).count-1 {
case 0: //no decimals
return true
case 1: //if adding decimal, only allow if no existing decimal
if let existingText = textField.text{
return existingText.componentsSeparatedByString(decimalSeparator).count <= 1
}
else {return true}
default: //invalid decimals
return false
}
}
return false
}
【讨论】：
以下是我在 Swift 3.0 中使用的代码，改编自 H 先生的代码。差异是因为：
a) Swift 3.0 中的委托函数声明已更改。 New declaration here
b) NSCharacterSet 声明已更改。
func textField(_ shouldChangeCharactersIntextField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool
{
let inverseSet = NSCharacterSet(charactersIn:"0123456789").inverted
let components = string.components(separatedBy: inverseSet)
let filtered = components.joined(separator: "")
return string == filtered
}
【讨论】：
我已经编辑了 Raj Joshi 的版本以允许使用一个点或一个逗号：
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let inverseSet = CharacterSet(charactersIn:"0123456789").inverted
let components = string.components(separatedBy: inverseSet)
let filtered = components.joined(separator: "")
if filtered == string {
return true
} else {
if string == "." || string == "," {
let countDots = textField.text!.components(separatedBy:".").count - 1
let countCommas = textField.text!.components(separatedBy:",").count - 1
if countDots == 0 && countCommas == 0 {
return true
} else {
return false
}
} else {
return false
}
}
}
【讨论】：
如果您想允许小数分隔符和/或负数，您可以使用此代码。 但此代码允许示例：“34”。 （末尾的小数分隔符）同时更改文本。所以你必须添加一些代码示例：textFieldShouldReturn 或 textFieldShouldEndEditing 委托函数。
用 Swift 4 编写的代码，但我认为这与 Swift 3 兼容。
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let text = textField.text else {
return true
}
let replaced = (text as NSString).replacingCharacters(in: range, with: string)
let decimalSeparator = NSLocale.current.decimalSeparator ?? ""
// When user wants to delete las character
if replaced == "" || replaced == "-" || replaced == "-0" {
textField.text = "0"
return false
}
// When text contains 0 before replace except "0."
if replaced != "0" + decimalSeparator && replaced.hasPrefix("0") && text.underestimatedCount == 1 {
textField.text = replaced.substring(from: replaced.index(after: replaced.startIndex))
return false
}
// When user wants to delete minus sign
if text.hasPrefix("-") && text.substring(from: text.index(after: text.startIndex)) == replaced {
return false
}
// When user wants to delete before decimal separator
if replaced.hasPrefix(decimalSeparator) || replaced.hasPrefix("-" + decimalSeparator) {
return false
}
// When user wants to add zero the beginning of number... but allowing "0." or "-0." numbers
let testReplaced = replaced.hasPrefix("-") ? replaced.substring(from: replaced.index(after: replaced.startIndex)) : replaced
if testReplaced.count >= 2 && testReplaced.hasPrefix("0") && !testReplaced.hasPrefix("0" + decimalSeparator) {
return false
}
// Every other cases
let allowDecimal = self.allowFloat ? (decimalSeparator == "." ? "\\.?" : decimalSeparator + "?") : ""
let allowSign = self.allowSigned ? "-?" : ""
let pattern = "\(allowSign)[0-9]+\(allowDecimal)([0-9]+)?"
do {
let regexRange = (replaced as NSString).range(of: replaced)
let regex = try NSRegularExpression(pattern: pattern, options: [])
let matches = regex.matches(in: replaced, options: [], range: regexRange)
return matches.count == 1 && matches.first!.range == regexRange
}
catch {}
return false
}
如果你不想允许小数或负数，你必须用下一行替换两个变量
let allowDecimal = ""
let allowSign = ""
【讨论】：
允许一些字符
func CheckAddress(string:String) -> Bool {
let numberOnly = NSCharacterSet.init(charactersIn: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-@,&#/")
let stringFromTextField = NSCharacterSet.init(charactersIn: string)
return numberOnly.isSuperset(of: stringFromTextField as CharacterSet)
}
print("\(CheckAddress(string: "123"))") //True
print("\(CheckAddress(string: "asdf-"))") //True
print("\(CheckAddress(string: "asd123$"))") //false
【讨论】：
以下解决方案有两个好处：
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
return NumberFormatter().numberFrom(text: (textField.text ?? "") + string) != nil
}
【讨论】：
Swift 2.0
func textField(textField: UITextField,
shouldChangeCharactersInRange range: NSRange,
replacementString string: String) -> Bool {
let inverseSet = NSCharacterSet(charactersInString:"0123456789").invertedSet
let components = string.componentsSeparatedByCharactersInSet(inverseSet)
let filtered = components.joinWithSeparator("")
return string == filtered
}
【讨论】：
func isValidNumber(str:String) -> Bool{
if str.isEmpty {
return false
}
let newChar = NSCharacterSet(charactersInString: str)
let boolValid = NSCharacterSet.decimalDigitCharacterSet().isSupersetOfSet(newChar)
if boolValid{
return true
}else{
let lst = str.componentsSeparatedByString(".")
let newStr = lst.joinWithSeparator("")
let currentChar = NSCharacterSet(charactersInString: newStr)
if lst.count == 2 && !lst.contains("") && NSCharacterSet.decimalDigitCharacterSet().isSupersetOfSet(currentChar){
return true
}
return false
}
}
如果有的话，把这个函数放在你的“提交”或“保存”方法中。
【讨论】：