自定义UITextView
lazy var txvRemark: MJPlaceTextView = {
let view = MJPlaceTextView(placeholder: self.strPlaceholder, placeholderColor: UIColor.lightGray, frame: CGRect(x: 0, y: 15, width: kSCREEN_WIDTH, height: 110))
NotificationCenter.default.addObserver(self, selector: #selector(textDidChange), name: .UITextViewTextDidChange, object: view.palceholdertextView)
view.palceholdertextView.text = self.strContent
view.palceholdertextView.mj_becomeFirstResponder { }
return view
}()
view.addSubview(txvRemark)