Question

我无法将此代码转换为场景生成器...

问题出在事件处理程序中。...

我没有得到如何在Java中使用ConfirmCloseEventHandler事件处理程序 FX场景构建器...

提前谢谢。

主要我不能在fxml控制器中使用这些事件处理程序...

public class Javafxpopupmessage extends Application {

private Stage mainStage;

@Override
public void start(Stage stage) throws Exception {
    this.mainStage = stage;
    stage.setOnCloseRequest(confirmCloseEventHandler);

    Button closeButton = new Button("Close Application");
    closeButton.setOnAction(event ->
            stage.fireEvent(
                    new WindowEvent(
                            stage,
                            WindowEvent.WINDOW_CLOSE_REQUEST
                    )
            )
    );

    StackPane layout = new StackPane(closeButton);
    layout.setPadding(new Insets(100));
    stage.setScene(new Scene(layout));
    stage.show();
}

private EventHandler<WindowEvent> confirmCloseEventHandler = event -> {
    Alert closeConfirmation = new Alert(
            Alert.AlertType.CONFIRMATION,
            "Are you sure you want to exit?"
    );
    Button exitButton = (Button) 
    closeConfirmation.getDialogPane().lookupButton(
            ButtonType.OK
    );
    exitButton.setText("Exit");
    closeConfirmation.setHeaderText("Confirm Exit");
    closeConfirmation.initModality(Modality.APPLICATION_MODAL);
    closeConfirmation.initOwner(mainStage);

    // normally, you would just use the default alert positioning,
    // but for this simple sample the main stage is small,
    // so explicitly position the alert so that the main window can still be 
   seen.
   // closeConfirmation.setX(mainStage.getX());
    //closeConfirmation.setY(mainStage.getY() + mainStage.getHeight());

    Optional<ButtonType> closeResponse = closeConfirmation.showAndWait();
    if (!ButtonType.OK.equals(closeResponse.get())) {
        event.consume();
    }
    };
    public static void main(String[] args) {
    launch(args);
    }

     }

Answer 1

通过fxml为主要阶段注册一些处理程序只能用不好的技巧来完成，因为FXMLLoader只能访问自己创建的对象。

您可以在场景中某个节点的Node.scene属性中添加一个侦听器，并在设置场景后立即将其添加到该场景的window属性中，并在其进入后立即访问窗口分配，这对于在start方法中使用更简单的代码即可完成的事情来说非常复杂。

除了这种黑客之外，您将无法在start方法中注册该事件处理程序（或将Stage传递给控制器，导致代码比发布的代码复杂）。

关于关闭按钮onAction事件：您可以将控制器的方法用作处理程序：

fxml

<StackPane xmlns:fx="http://javafx.com/fxml" fx:controller="mypackage.MyController">
    <children>
        <Button text="Close Application" onAction="#close"/>
    </children>
    <padding>
        <Insets topRightBottomLeft="100"/>
    </padding>
</StackPane>

控制器

package mypackage;

...

public class MyController {
    @FXML
    private void close(ActionEvent event) {
        Node source = (Node) event.getSource();
        Window window = source.getScene().getWindow();
        window.fireEvent(new WindowEvent(
                                window,
                                WindowEvent.WINDOW_CLOSE_REQUEST));
    }
}

将Java FX代码转换为Java SceneBuilder

1 个答案:

fxml

控制器