如何将FXML Controller1中创建的对象传递给内部FXML控件的Controller2

Question

我有JavaFX 2.0应用程序,它包含两个FXML文件,以及两个用于它们的控制器+一个"主".java文件.

在开始时,FXML1被初始化,如下所示:

public void start(Stage stage) throws Exception {
    stage.setTitle("Demo Jabber JavaFX Chat");

    Parent root = FXMLLoader.load(getClass().getResource("fxml_example.fxml"),
        ResourceBundle.getBundle("fxmlexample.fxml_example"));        
    Scene scene = new Scene(root, 226, 264);
    stage.setScene(scene);
    scene.getStylesheets().add("fxmlexample/fxmlstylesheet.css");
    stage.show();
}

然后,当单击来自scene1的按钮时,在Controller1类的事件处理程序中,我更改scene1 root,以显示用户的新gui-view.在这个控制器中我初始化了一些对象.例如这样:

public class FXMLExampleController {
   //some fields...
   private MySuperObject c;
   @FXML protected void handleSubmitButtonAction(ActionEvent event) {
    //some fields...
    c = new MySuperObject(); //here i initialize my object, i'm interested in
    try {
        c.login(username, password); // some actions with this object, which i need to make.
        Scene cc = buttonStatusText.getScene();
        Parent root = null;
        try {
            //changing a scene content...
            root = FXMLLoader.load(getClass().getResource("fxml_example2.fxml"),
            ResourceBundle.getBundle("fxmlexample.fxml_example"));
        } catch (IOException ex) {
            Logger.getLogger(FXMLExampleController.class.getName()).log(Level.SEVERE, null, ex);
        }
        cc.setRoot(root);
      }

之后,我必须在下一个场景中对该对象进行一些处理,并且它必须不是同一个类的新实例,而是对象,我已经在第一个场景上初始化了.

我理解如何使用"标准java"来完成所有这些,但我对使用JavaFX + FXML的这项任务感到困惑.

Answer 1

在FX 2.2中引入了用于控制器节点的新API:

// create class which is both controller and node
public class InnerFxmlControl extends HBox implements Initializable {
  @FXML public ComboBox cb;

  public InnerFxmlControl () {
     FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("fxml_example2.fxml"));
     fxmlLoader.setRoot(this);
     fxmlLoader.setController(this);
     try {
         fxmlLoader.load();            
     } catch (IOException exception) {
         throw new RuntimeException(exception);
     }
  }

使用下一个fxml(注释标记fx:root):

<fx:root type="javafx.scene.layout.HBox" xmlns:fx="http://javafx.com/fxml">
  <children>
    <ComboBox fx:id="cb" />
  </children>
</fx:root>

通过这个,您创建了一个新控件,您可以将其用作常规JavaFX控件.例如在你的情况下:

@FXML protected void handleSubmitButtonAction(ActionEvent event) {
    // you just create new control, all fxml tricks are encapsulated
    InnerFxmlControl root = new InnerFxmlControl();
    // and you can access all its' methods and fields including matched by @FXML tag:
    root.cb.getItems().add("new item");

    Scene cc = buttonStatusText.getScene();
    cc.setRoot(root);
  }

并在fxml中:

<InnerFxmlControl />