UITextView length issue - swift

Question

I've a UITextView with scroll enabled, I can change font and size of the text inside. So, How can I set a text limit? I've already tried to set max row and max number of character but it doesn't working because I need to set a size limit of the text, How can I do this?

Answer 1

You have to implement the UITextViewDelegate:
class ViewController: UIViewController, UITextViewDelegate {
and then set the delegate of the textView in the viewDidLoad-method:
yourTextView.delegate = self
After that you can use the shouldChangeTextInRange method to check the letters:
func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
let maxtext: Int = 140
//If the text is larger than the maxtext, the return is false
// Swift 2.0
return textView.text.characters.count + (text.characters.count - range.length) <= maxtext
// Swift 1.1
// return countElements(textView.text) + (countElements(text.length) - range.length) <= maxtext
}
The nice part in this solution is, that you can even control cut/copy and paste. So the user can't trick the field to accept more letters by copying.

Answer 2

1) class ViewController: UIViewController, UITextViewDelegate {
2) textView.delegate = self
3)
func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
let maxCharacter: Int = 1000
return (textView.text?.utf16.count ?? 0) + text.utf16.count - range.length <= maxCharacter
}

Answer 3

Usually you'd conform to the UITextFieldDelegate protocol, specify your view controller as the delegate for the UITextField (specifying this either in IB or in code) and then implement a shouldChangeCharactersInRange that considers the length of the string:
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let oldString = textField.text ?? ""
let startIndex = oldString.startIndex.advancedBy(range.location)
let endIndex = startIndex.advancedBy(range.length)
let newString = oldString.stringByReplacingCharactersInRange(startIndex ..< endIndex, withString: string)
return newString.characters.count <= kMaxLength
}
If, on the other hand, you want to control the amount of text entered to conform to the size of the control, you could use the aforementioned shouldChangeTextInRange, but use sizeWithAttributes to dictate whether that method returns true or false rather than the number of characters.
This isn't quite right, but it illustrates the basic idea:
func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
let oldString = textField.text ?? ""
let startIndex = oldString.startIndex.advancedBy(range.location)
let endIndex = startIndex.advancedBy(range.length)
let newString = oldString.stringByReplacingCharactersInRange(startIndex ..< endIndex, withString: string)
let stringSize = newString.sizeWithAttributes([NSFontAttributeName : textField.font ?? UIFont.systemFontSize()])
return stringSize.width < textField.editingRectForBounds(textField.bounds).size.width
}