如何在控制器文件中的.fxml文件中将对象称为对象？

Question

I am making a stopwatch program and I want to set a photo for rotation. The problem is, is that I dont know how to call the photo in the controller file. It just tells me that it cannot find symbol.

Heres the photo I want to call from my .fxml file

 <ImageView fx:id="hand">
     <image>
        <Image url="@hand.png"/>
     </image>
  </ImageView>

And heres where I call it in my controller file, but I get an error.

@FXML
 private void updateStopwatch(){
    elapsedTime++;
    Integer rotation = elapsedTime * 6;
    hand.setRotate(rotation);      


 }

Thanks for the help in advance. The error I get is the following :

hand.setRotate(rotation); 
^^^^
Cannot find symbol hand

Answer 1

When you have given the fxml object you want to inject into your controller the correct property fx:id="hand" you need to declare that id as a property in your controller class.

public class MyController {
    @FXML private ImageView hand;

    private void updateStopwatch(){
        elapsedTime++;
        Integer rotation = elapsedTime * 6;
        hand.setRotate(rotation);      
    }
}

In your fxml file you must refer to the controller(MyController) by adding this attribute in root element:

fx:controller="some.package.MyController"

your fxml file may only refer to one controller.