class PlaceStrTextView: UIView,UITextViewDelegate{        var palceStr = "即将输入的信息" //站位文字    var inputStr = "" //输入的信息        //创建一个textView    lazy var textView:UITextView = {        let tv = UITextView()        tv.delegate = self        tv.text = self.palceStr        tv.textColor = UIColor.gray        tv.backgroundColor = UIColor.clear        tv.font = UIFont.systemFont(ofSize: 15)        return tv    }()        //私有方法    func overrideSelf(frame: CGRect) {        self.frame = frame        addTextView()    }        //添加textView    func addTextView(){        self.textView.frame = CGRect(x: 0, y: 0, width: self.frame.width, height: self.frame.height)        self.addSubview(self.textView)    }        func textViewDidBeginEditing(_ textView: UITextView) {        if textView.text == palceStr { //一旦开始编辑就将textView滞空并将颜色改为黑色            textView.text = ""        }        textView.textColor = UIColor.black    }        func textViewDidEndEditing(_ textView: UITextView) {        if textView.text == "" {//如果用户没有输入任何信息就显示站位字符串            textView.text = palceStr            textView.textColor = UIColor.gray        }else{//一旦输入了信息你则颜色变成黑色            textView.textColor = UIColor.black        }    }        func hiddenKeyBoard(){        (UIApplication.shared.delegate as! AppDelegate).window?.endEditing(true)        inputStr = textView.text    }    }

　

//调用示例      @IBOutlet weak var textView: PlaceStrTextView!    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view.        textView.palceStr = "埃及的妇女节阿萨德来看风景安东尼设计开发"        textView.overrideSelf(frame: textView.frame)    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }    @IBAction func tapAction(_ sender: Any) {        textView.hiddenKeyBoard()        print(textView.inputStr)    }