Erlauben Sie nur alphanumerische Zeichen für ein UITextField

Dies ist, wie ich es mache:

//Define some constants:
#define ALPHA                   @"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
#define NUMERIC                 @"1234567890"
#define ALPHA_NUMERIC           ALPHA NUMERIC

//Make sure you are the text fields 'delegate', then this will get called before text gets changed.
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    //This will be the character set of characters I do not want in my text field.  Then if the replacement string contains any of the characters, return NO so that the text does not change.
    NSCharacterSet *unacceptedInput = nil;

    //I have 4 types of textFields in my view, each one needs to deny a specific set of characters:
    if (textField == emailField) {
        // Validating an email address doesnt work 100% yet, but I am working on it....  The rest work great!
        if ([[textField.text componentsSeparatedByString:@"@"] count] > 1) {
            unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:[ALPHA_NUMERIC stringByAppendingString:@".-"]] invertedSet];
        } else {
            unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:[ALPHA_NUMERIC stringByAppendingString:@".!#$%&'*+-/=?^_`{|}~@"]] invertedSet];
        }
    } else if (textField == phoneField) {
        unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:NUMERIC] invertedSet];
    } else if (textField == fNameField || textField == lNameField) {
        unacceptedInput = [[NSCharacterSet characterSetWithCharactersInString:ALPHA] invertedSet];
    } else {
        unacceptedInput = [[NSCharacterSet illegalCharacterSet] invertedSet];
    }

    //If there are any characters that I do not want in the text field, return NO.
    return ([[string componentsSeparatedByCharactersInSet:unacceptedInput] count] <= 1);
}

Check-out die UITextFieldDelegate Referenz zu.

InformationsquelleAutor der Antwort chown

Swift 3-version

Derzeit akzeptierte Antwort Ansatz:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    //Get invalid characters
    let invalidChars = NSCharacterSet.alphanumerics.inverted

    //Attempt to find the range of invalid characters in the input string. This returns an optional.
    let range = string.rangeOfCharacter(from: invalidChars)

    if range != nil {
        //We have found an invalid character, don't allow the change
        return false
    } else {
        //No invalid character, allow the change
        return true
    }
}

Anderen, gleichermaßen funktionalen Ansatz:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {

    //Get invalid characters
    let invalidChars = NSCharacterSet.alphanumerics.inverted

    //Make new string with invalid characters trimmed
    let newString = string.trimmingCharacters(in: invalidChars)

    if newString.characters.count < string.characters.count {
        //If there are less characters than we started with after trimming
        //this means there was an invalid character in the input. 
        //Don't let the change go through
        return false
    } else {
        //Otherwise let the change go through
        return true
    }

}

InformationsquelleAutor der Antwort teradyl

Für Swift:
Verbinden Sie Ihren UITextField für die Veranstaltung EditingChanged zu folgenden IBAction:

@IBAction func ActionChangeTextPassport(sender:UITextField){
    if sender == txtPassportNum{
        let newStr = sender.text?.stringByTrimmingCharactersInSet(NSCharacterSet.alphanumericCharacterSet().invertedSet)
        if newStr?.characters.count < sender.text?.characters.count{
            sender.text = newStr
        }
    }
}

InformationsquelleAutor der Antwort FARAZ