javafx循環while按鈕按下

Question

當按下按鈕時，我無法獲得此循環，並且釋放按鈕時停止循環。

btnUp.pressedProperty().addListener((observable, wasPressed, pressed) -> { 
    System.out.println("changed"); 
    if (pressed) { 
     System.out.println("pressed"); 
     while(btnUp.isArmed()){ 
      try   
      { 
       Thread.sleep(1000); 
      } 
      catch(InterruptedException ex) 
      { 
       Thread.currentThread().interrupt(); 
      } 
      //moveflag = false; 
      System.out.println("pressed"); 
     } 
    } else { 
     System.out.println("released"); 
    } 
}); 

Answer 1

1. 不要使用Thread.sleep（）方法的UI操作中，它會阻止所有UI繪製
2. 不同時裏面的ChangeListener使用，只是有一個獨立的循環，檢查按鈕的狀態

3. 時間表最適合這樣的循環

   public void start(Stage stage) { 
   Button btn = new Button("Press me"); 
   
   Timeline timeline = new Timeline(new KeyFrame(Duration.seconds(1), (ActionEvent event) -> { 
       // this code will be called every second 
       System.out.println(btn.isPressed() ? "pressed" : "released"); 
   })); 
   timeline.setCycleCount(Timeline.INDEFINITE); 
   timeline.play(); 
   
   
   StackPane root = new StackPane(); 
   root.getChildren().add(btn); 
   
   Scene scene = new Scene(new StackPane(btn), 300, 250); 
   stage.setTitle("Hello World!"); 
   stage.setScene(scene); 
   stage.show(); 
   

   }