将TextView限制在一定数量的number 2中

Question

我需要限制我的文本视图只有6行。如何将文本视图限制为6行？我已经设置了一些字符限制50个字符无论如何。

Answer 1

要做到这一点很少简单。试试下面的代码

inputTextView.textContainer.maximumNumberOfLines = 6
inputTextView.textContainer.lineBreakMode = .ByWordWrapping

Answer 2

对于斯威夫特4来说，这个方法没有任何错误：

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    let existingLines = textView.text.components(separatedBy: CharacterSet.newlines)
    let newLines = text.components(separatedBy: CharacterSet.newlines)
    let linesAfterChange = existingLines.count + newLines.count - 1
    return linesAfterChange <= textView.textContainer.maximumNumberOfLines
}

如果您还想限制字符：

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        let existingLines = textView.text.components(separatedBy: CharacterSet.newlines)
        let newLines = text.components(separatedBy: CharacterSet.newlines)
        let linesAfterChange = existingLines.count + newLines.count - 1
        if(text == "\n") {
            return linesAfterChange <= textView.textContainer.maximumNumberOfLines
        }

        let newText = (textView.text as NSString).replacingCharacters(in: range, with: text)
        let numberOfChars = newText.count
        return numberOfChars <= 30 // 30 characters limit
    }
}

不要忘记在viewDidLoad中添加您希望限制的行数

txtView.textContainer.maximumNumberOfLines = 2