override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after loading the view. view.backgroundColor = UIColor.white  //應用內實現粘貼，這個txt用來測試的 let txt = UITextField(frame: CGRect(x: 100, y: 100, width: 100, height: 33)) txt.backgroundColor = UIColor.yellow txt.placeholder = "shuru" view.addSubview(txt)  //1.測試剪切板 testPasteBoard(str: "123")   }  /// 測試剪切板，實現代碼拷貝內容 /// 結論：應用程序內可實現長按輸入框后，粘貼，應用程序外依然可以。 func testPasteBoard(str:String) {  //就這兩句話就實現了 let paste = UIPasteboard.general paste.string = str   }