UITextField - Allow only numbers and punctuation input/keypad

问题

I have tried the code below but that only allows for numbers on the keypad to be inputted. My app requires the keypad to use a period/full stop (for money transactions). The code I tried is:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

   NSCharacterSet *nonNumberSet = [[NSCharacterSet decimalDigitCharacterSet] invertedSet];

     if ([string rangeOfCharacterFromSet:nonNumberSet].location != NSNotFound)
      {
         return NO;
    }
   return YES;

}

Thanks for any help.

回答1:

Try this

Make a macro

#define ACCEPTABLE_CHARACTERS @"0123456789."

And use it

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string  {

    if (textField==textFieldAmount)
    {
        NSCharacterSet *cs = [[NSCharacterSet characterSetWithCharactersInString:ACCEPTABLE_CHARACTERS] invertedSet];

        NSString *filtered = [[string componentsSeparatedByCharactersInSet:cs] componentsJoinedByString:@""];

        return [string isEqualToString:filtered];
    }
    return YES;
}

回答2:

Just use

[textField setKeyboardType:UIKeyboardTypeNumbersAndPunctuation];

after creating your textfield.

回答3:

How about a custom character set? Something like this:

NSCharacterSet *testChars = [NSCharacterSet characterSetWithCharactersInString:@"0123456789+*#-() "];

Because setting the keyboard type is pretty useless on iPad...

回答4:

In Swift 3:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let allowedCharacters = "0123456789!@#$%^&*()_+~:{}|\"?><\\`,./;'[]=-"
    return allowedCharacters.contains(string) || range.length == 1
}

来源：https://stackoverflow.com/questions/20122455/uitextfield-allow-only-numbers-and-punctuation-input-keypad