Binding Label property to Image property using javafx concurrency Task<Void>

Question

I'm trying to update my JavaFX GUI after every 1 second using Task concuurency. I've icons 1.png , 2.png , 3.png and so on. I'm using a while loop increments i++ . I want to display those icons after every 1 second. I don't know how to update Image. I'm using label.setGraphic() method. I don't know how to use bind property here. I may be stark wrong. Please help me.

@Override
public void start() {
  ...
  image = new Image(getClass().getResourceAsStream("images/1.png"));
  imv=new ImageView(image);
  label1 = new Label();
  label1.setGraphic(imv);
  monitor(); //A SEPARATE METHOD CONTAINING TASK CODE
  ...
  new Thread(task1).start();
}

...
public void monitor() {
  task1=new Task<Void>() {
    @Override
    protected Void call() {
      int i=1;
      while(true) {
        try {
          Thread.sleep(1000);
          updateMessage(""+i+".png");
          System.out.println("i: "+i);
        }
        catch(Exception e) {
        }
        i++;
        }
     }
  };
  label1.textProperty().bind(task1.messageProperty());
  ...
}

Answer 1

The error is that you can not bind a ReadOnlyStringProperty to an ObjectProperty<Image> .

You should add a change listener ( docs ) to the task message property ( docs ) and create an image which you then apply to your image view:

public void monitor() {
    task1 = new Task<Void>() {
        @Override
        protected Void call() {
            System.out.println("run called");
            int i = 1;
            while (true) {
                try {
                    Thread.sleep(1000);
                    updateMessage(i + ".png");
                    System.out.println("i: " + i);
                } catch (Exception e) {

                }
                i++;
            }
        }
    };
    task1.messageProperty().addListener((observable, oldValue, newValue) -> {
        System.out.println(newValue);
        Image image = new Image(getClass().getResourceAsStream("images/" + newValue));
        imv.setImage(image);
    });
}

EDIT:

The ChangeListener is represented by that Lambda expression in the given snippet. Please read the provided docs for more information.