Swift5：TextField 最小和最大字符限制验证

Question

I am trying to validate Minimum 6 characters and Maximum 20 characters in TextField. Below is the code validation .

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    let curruntCharachterCount = textField.text?.count ?? 0
    if range.length + range.location > curruntCharachterCount{
        return false
    }
    let newLength = curruntCharachterCount + string.count - range.length
    return newLength <= 20
}

How should i set Minimum character length validation. Please suggest.

Answer 1

You can do like below

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        
        if let text = textField.text,
           let textRange = Range(range, in: text) {
            let updatedText = text.replacingCharacters(in: textRange,with: string)
            if updatedText.count <= 6 {
                print("minimum 6")
            }else if updatedText.count >= 20{
                print("max 20")
                return false
            }
        }
        return true
    }