Setting maximum number of characters of `UITextView ` and `UITextField `

Question

I'd like to set a maximum number of characters allowed to be typed both in a UITextView and a UITextField. This number will be then shown in a little label (for user's reference, Twitter Style.)

Solution 1

Update Swift 4.X

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    let newText = (textView.text as NSString).replacingCharacters(in: range, with: text)
    let numberOfChars = newText.count
    return numberOfChars < 10    // 10 Limit Value
}

Try this out:

func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
    let newText = (textView.text as NSString).stringByReplacingCharactersInRange(range, withString: text)
    let numberOfChars = newText.characters.count // for Swift use count(newText)
    return numberOfChars < 10;
}

Solution 2

SWIFT 4

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
     let newText = (textView.text as NSString).replacingCharacters(in: range, with: text)
     return newText.count < 10
}

Solution 3

Swift 4:

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
  let newText = (textView.text as NSString).replacingCharacters(in: range, with: text)
  return newText.count <= 70
}

Solution 4

Try this out:-

 func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
    print("chars \(textView.text.characters.count) \( text)")

    if(textView.text.characters.count > 20 && range.length == 0) {
        print("Please summarize in 20 characters or less")
        return false;
    }

    return true;
}

Solution 5

Swift 3.0

Just override this UITextFieldDelegate function, set the desired characterLimit variable and you are good to go:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool 
{        
        let characterLimit = 5
        let newText = NSString(string: textField.text!).replacingCharacters(in: range, with: string)
        let numberOfChars = newText.characters.count
        return numberOfChars < characterLimit
}

View more solutions

Comments

[rmaddy]

This is correct but why is the variable named numberOfLines when it is the number of characters?

[William Kinaan]

yes this is correct, i forgot about the number of lines

[rmaddy]

@WilliamKinaan What number of lines? There's nothing in the question about limiting the number of lines.

[Abhinav]

Thanks @rmaddy for pointing out. It was a typo in a rush :-), corrected it now!

[biggreentree]

I added this code in ViewDidLoad and replaced textView: UITextView with myMessageTextView is it right? Now I got this error String does not have a member named 'characters'. I'm using swift 1.2 at now, could be a problem?

[Abhinav]

Yes, as I mentioned in my code. For Swift use count(newText). I am using Swift 2.

[Abhinav]

Hey ... 1 minute, you said you added my code in viewDidLoad? Well thats not correct. In your viewDidLoad you would add your view controller as delegate to your UITextField something like this myMessageObjectLabel.delegate = self. The code that I have shared above is a delegate call back from UITextField - add in your class file as an independent function and it should get called back for each character typed in by user in your text field.

[Abhinav]

You need to conform to UITextViewDelegate protocol. I guess by mistake you added text filed delegate. Please check that out. @biggreentree

[Abhinav]

I am sure its very simple stuff. Would it be possible for you to share the project on github? I can take a look. @biggreentree

[Abhinav]

Hey, your method signature is totally off. Take a look at my post. You should not use self.startingMessageTextView , instead it should be UITextView. Use my method word by word. @biggreentree

[biggreentree]

you are totally right, I changed it because in my mind I was acting only on that selected UITextView everything works great! thanks I'll do the same on my UITextField for object

[Abhinav]

Let us continue this discussion in chat.

[Roberto]

Shouldn't the last line be return numberOfChars <= 10; (the less-than symbol should be less-than-or-equal-to)?

[Steve]

@Abhinav how to restrict the copied text in here? like, clipboard got 2000 characters string where textview allows 1500 character, so when i paste the long string it let the textview empty instead of copying 1500 characters.

[Lance Samaria]

in Swift 4 its: let numberOfChars = newText.count

[Yaroslav Dukal]

@LanceSamaria thanks, updated my answer to Swift 4, since Swift 3 is no longer relative..

[Yaroslav Dukal]

what's adjust frames for ?

[Swany]

If you want to allow the user to delete chars when they "are over the limit" (can happen if you lower the char limit and user is editing with old (longer text), add a guard...guard !text.isEmpty else { return true }