How to switch javafx application controller without reloading FXML file?

问题

I have two main screens in my application build with FXML ( loginWindow and mainWindow ). User can

login from loginWindow to mainWindow
logout from mainWindow to loginWindow

Right now I'm using this method to change scene via fxml file

private Initializable replaceSceneContent(String fxml) throws Exception {

    FXMLLoader loader = new FXMLLoader();
    InputStream in = WRMS.class.getResourceAsStream(fxml);
    loader.setBuilderFactory(new JavaFXBuilderFactory());
    loader.setLocation(WRMS.class.getResource(fxml));

    AnchorPane page;
    try {
        page = (AnchorPane) loader.load(in);
    } finally {
        in.close();
    }

    Scene scene = new Scene(page);

    mainStage.setScene(scene);
    mainStage.sizeToScene();
    return (Initializable) loader.getController();
}

And this methods to switch to login and main window:

private void gotoMain() {        
try {                
    MainController mainController = (MainController) replaceSceneContent("Main.fxml");                
    mainController.setApp(this);
} catch (Exception ex) {
    ex.printStackTrace();                
}
}

private void gotoLogin() {        
try {
    LoginController login = (LoginController) replaceSceneContent("Login.fxml");
login.setApp(this);
} catch (Exception ex) {
    log.error(WRMS.class.getName() + ex);

}
}

It is working fine. Only one problem is that my method replaceSceneContent every time it is called is creating new instance of controller. I would like to have only one instance of each controller and switch between them. Is it possible? If yes, how to use FXML loader in this case?

回答1:

You can create a controller instance and then set the controller into the loader.

You could get the controller using a singleton pattern if you wanted only a single instance of the controller for an application.

Sample code from Passing Parameters JavaFX FXML

CustomerDialogController dialogController = 
    new CustomerDialogController(param1, param2);

FXMLLoader loader = new FXMLLoader(
    getClass().getResource(
        "customerDialog.fxml"
    )
);
loader.setController(dialogController);

Pane mainPane = (Pane) loader.load();

来源：https://stackoverflow.com/questions/20919691/how-to-switch-javafx-application-controller-without-reloading-fxml-file

标签

javafx

fxml