how to limit uitextfield character range upto 10 digit - ios

Question

I just want to know how to limit uitextfield range, i.e I have one textbox in that I enter values 10 digit. If I try to type more than 10 digit my textfield should not accept the values. To be very simple I want only 10 digit should be enter in the textfield.
I work out this code but its not worked for me:
- (BOOL)textField:(UITextField *) textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSUInteger oldLength = [textField.text length];
NSUInteger replacementLength = [string length];
NSUInteger rangeLength = range.length;
NSUInteger newLength = oldLength - rangeLength + replacementLength;
BOOL returnKey = [string rangeOfString: #"\n"].location != NSNotFound;
return newLength <= MAXLENGTH || returnKey;
}

Answer 1

To limit a text input's length implement this method of UITextFieldDelegate and check a text's length after changing:
- (BOOL) textField:(UITextField *)textField
shouldChangeCharactersInRange:(NSRange)range
replacementString:(NSString *)string {
NSString *resultText = [textField.text stringByReplacingCharactersInRange:range
withString:string];
return resultText.length <= 10;
}

Answer 2

In Swift 3.0
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
let charsLimit = 10
let startingLength = textField.text?.characters.count ?? 0
let lengthToAdd = string.characters.count
let lengthToReplace = range.length
let newLength = startingLength + lengthToAdd - lengthToReplace
return newLength <= charsLimit
}

Answer 3

Try below code that is restricted to 10 digital text.
- (BOOL)textField:(UITextField *) textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSInteger length = [textField.text length];
if (length>9 && ![string isEqualToString:#""]) {
return NO;
}
// This code will provide protection if user copy and paste more then 10 digit text
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
if ([textField.text length]>10) {
textField.text = [textField.text substringToIndex:10];
}
});
return YES;
}
Hope this help you.

Answer 4

Swift 3 Version
func textField(_ textField: UITextField, shouldChangeCharactersIn range:NSRange, replacementString string: String) -> Bool
{
let currentCharacterCount = textField.text?.characters.count ?? 0
if (range.length + range.location > currentCharacterCount){
return false
}
let newLength = currentCharacterCount + string.characters.count - range.length
return newLength <= 10
}

Answer 5

Try this.
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
if(range.length + range.location > textField.text.length)
{
return NO;
}
NSUInteger newLength = [textField.text length] + [string length] - range.length;
return (newLength > 10) ? NO : YES;}

Answer 6

You can use this...i hope it will help you/
-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
int lenght1 = code.text.length - range.length + string.length;
if (textField.text.length >= 4 && range.length == 0)
return NO;

Answer 7

I built a really nice subclass of UITextField to limit the number of characters inputted into a field. Here you go!:
public class NumberFormattedTextField : UITextField {
#IBInspectable public var maximumCharacters = 10 {
didSet {
format()
}
}
public override func awakeFromNib() {
format()
addTarget(self, action: "format", forControlEvents: .EditingChanged)
}
func format() {
let len = text.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)
// truncate for max characters if needed
if len > maximumCharacters {
text = text[1...maximumCharacters] // pulls in the last entered character and drops the first one off to preserve length
}
}
}
This depends on a subscript for String. Here's that too:
public extension String {
public subscript (r: Range<Int>) -> String? {
let l = self.lengthOfBytesUsingEncoding(NSUTF8StringEncoding)
if r.startIndex <= l && r.endIndex <= l {
return substringWithRange(Range(start: advance(startIndex, r.startIndex), end: advance(startIndex, r.endIndex)))
} else {
return nil
}
}
}

Answer 8

I have build a subclass based on the answer given by Oxcug without the need for creating an extension in String file and max characters length can be set from storyboard and from swift file as well.:
#IBDesignable class CustomTextField: UITextField {
#IBInspectable var maximumCharacters: Int = 80 {
didSet {
limitCharacters()
}
}
override func awakeFromNib() {
super.awakeFromNib()
limitCharacters()
addTarget(self, action: #selector(CustomTextField.limitCharacters), for: .editingChanged)
}
func limitCharacters() {
guard text != nil else {
return
}
if (text?.characters.count)! > maximumCharacters {
if let range = text?.index(before: (text?.endIndex)!) {
text = text?.substring(to: range)
}
}
}
}

Answer 9

Best Solution:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
return range.location < 10 //Here 10 is your character limit
}