我无法从另一个类访问，我在一个FXML文件中创建了两个不同控制器的窗格，第二个窗格必须在第一个窗格中移动，在Click Action上，我在第二个窗格中加载了一个FXML文件，也成功移动了窗格一次，但第二次我想从第二个控制器移动它，但它给了我一个NullPointerException .
这是我移动窗格的主控制器：
public class MainController implements Initializable {
@FXML
private Pane searchPane;
@FXML
private Pane secondPane;
private TranslateTransition nextTransition;
public Pane getSecondPane() {
return secondPane; // Accessing Pane with this getter method
}
/**
* Initializes the controller class.
*/
@Override
public void initialize(URL url, ResourceBundle rb) {
}
@FXML
private void nextBtnAction(ActionEvent event) {
try {
Parent pessFxml = FXMLLoader.load(getClass().getResource("firstPane.fxml"));
secondPane.getChildren().add(pessFxml);
nextTransition = new TranslateTransition(Duration.millis(300), secondPane);
nextTransition.setToX(searchPane.getLayoutX()-secondPane.getLayoutX());
nextTransition.play();
} catch (IOException ex) {
JOptionPane.showMessageDialog(null, "Form does not found" ,ex.toString(),0);
}
}
}
这是 SecondController 我正在访问窗格以便顺利地移回它，但它正在抛出 NullPointerException ：请告诉我如何解决这个问题
public class SecondController implements Initializable {
MainController mainControll;
/**
* Initializes the controller class.
*/
@Override
public void initialize(URL url, ResourceBundle rb) {
}
@FXML
private void backBtnPessAction(ActionEvent event) {
//here i am putting the second pane to move back
TranslateTransition back = new TranslateTransition(Duration.millis(300), mainControll.getSecondPane());
back.setToX(mainControll.getSecondPane().getLayoutX()-750);
back.play();
}
}
1 回答
MainController永远不会在SecondController中初始化 . 在nextBtnAction中创建第二个控制器时应该传递它 .MainController代码：
SecondController：