// 問題描述限制50個(gè)字

設(shè)置delegate

遵循UITextViewDelegate

代碼限制字?jǐn)?shù)不超過50

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        
        if text == "" {
            return true
        }
        if textView.text.count > 49 {
            return false
        }
        return true
    }