ios - 如何在 20 个字符后切断 TextView ？

Question

我试图将 TextView 中的字符数限制为 20 个。20 个之后它应该改为“...”。该函数未触发，我正在正确设置委托(delegate)。

动物类

cell.pn.text = np[indexPath.row]
cell.pn.selectable = false
cell.pn.delegate = self

Animal类的扩展

extension Animal : UITextViewDelegate{
func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
    return textView.text.characters.count + (text.characters.count - range.length) <= 20
    }
}

Answer 1

试试这个:

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
        let text = textField.text
        let newLength = text.characters.count + string.characters.count - range.length
        return newLength <= 20
    }