用 javafx 创建等待/通知窗口有什么好处？

Question

我只想创建一个弹出窗口并通过 for 循环更改内容； （对于每个删除的文件）。我想回答yes/no/noAll/yesAll。所以我需要一个 wait() 来显示带有第一部电影内容的弹出窗口。例如，如果我说“不”，我希望将 notify() 线程解锁，以达到第二部电影的目标。在这种情况下，弹出内容会随着第二部电影而变化，我再次等待（），直到我通过按钮等回答。

我尝试了很多东西都没有成功：/ 我得到这个错误：

Exception in thread "JavaFX Application Thread" java.lang.IllegalMonitorStateException
    at java.lang.Object.notifyAll(Native Method)
    at controllers.HomeController.notifyPopup(HomeController.java:150)
    at controllers.HomeController.lambda$1(HomeController.java:208)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)

我在dialog.notify() 遇到问题 也许我没有在同一个对话框对象上应用 notify() 但确实如此，不是吗？

提前感谢您的帮助

这是我的部分代码：在代码中搜索// LOOK HERE以查看主要行

public class HomeController {


  @FXML
  private Label home;

  @FXMLViewFlowContext
  private ViewFlowContext context;

  RenameFiles film;
  SimpleBooleanProperty  noAllProperty = new SimpleBooleanProperty(false);
  SimpleBooleanProperty  yesAllProperty = new SimpleBooleanProperty(false);
  SimpleBooleanProperty  continuePopup = new SimpleBooleanProperty(false);
  ArrayList<Path> arrayFile = new ArrayList<Path>();
  Stage stage;
  Boolean firstFile = false;
  JFXDialogLayout content;
  JFXDialog dialog;

  @PostConstruct
  public void init() throws FlowException, VetoException {
    Settings settings = (Settings) context.getRegisteredObject("Settings");
    content = new JFXDialogLayout();
    dialog = new JFXDialog((StackPane) context.getRegisteredObject("ROOT"), content, JFXDialog.DialogTransition.CENTER);

    home.setOnDragOver(new EventHandler<DragEvent>() {
      @Override
      public void handle(DragEvent event) {
        Dragboard dragboard = event.getDragboard();
        if (dragboard.hasFiles()) {
          event.acceptTransferModes(TransferMode.ANY);
        } else {
          event.consume();
        }
      }
    });

    // Dropping over surface
    home.setOnDragDropped(new EventHandler<DragEvent>() {
      @Override
      public void handle(DragEvent event) {
        Dragboard dragboard = event.getDragboard();
        boolean success = false;
        if (dragboard.hasFiles()) {
          arrayFile = new ArrayList<Path>();
          success = true;
          noAllProperty.set(false);
          yesAllProperty.set(false);
          dragboard.getFiles().forEach(file -> {
            if(Files.isDirectory(file.toPath())){
              try(Stream<Path> paths = Files.walk(Paths.get(file.toURI()))) {
                paths.forEach(filePath -> {
                  if (Files.isRegularFile(filePath)) 
                  arrayFile.add(filePath);
                });
              } catch (IOException e) {
                e.printStackTrace();
              } 
            }else if (Files.isRegularFile(file.toPath()))
            arrayFile.add(file.toPath());

          });
        }
        event.setDropCompleted(success);
        event.consume();

        arrayFile.forEach(file -> {
          film = new RenameFiles(new File(file.toString()), settings);
          if(!noAllProperty.getValue()){
            if(film.getNameWithoutExt().length() > 0){
              if(!yesAllProperty.getValue()){
                    try {
                        firstFile = true;
                        contentPopup();

                        if(firstFile) {
                          dialog.show();
                          dialog.setOverlayClose(false);
                          firstFile = false;
                        }
                 // LOOK HERE
                        waitPopup(dialog);

                    } catch (FlowException | InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }           
              }else{
                film.applyRename(film.getCleanName());
              }
            }
          }
        });
      }
    });
  }
  public synchronized void waitPopup(JFXDialog dialog) {
        // This guard only loops once for each special event, which may not
        // be the event we're waiting for.
        while(!continuePopup.getValue()) {
            try {
                dialog.wait();
            } catch (InterruptedException e) {}
        }
    }

  public synchronized void notifyPopup(JFXDialog dialog) {
        continuePopup.setValue(true);
        dialog.notifyAll();
    }

  private void contentPopup() throws FlowException, InterruptedException{

    JFXButton buttonYesPopupRename = new JFXButton("Yes");
    buttonYesPopupRename.setPrefHeight(30);
    buttonYesPopupRename.setPrefWidth(70);
    buttonYesPopupRename.setId("buttonYesPopupRename");
    buttonYesPopupRename.setButtonType(ButtonType.RAISED);
    buttonYesPopupRename.setOnAction(e -> { film.applyRename(film.getCleanName());continuePopup.setValue(true);notifyPopup(dialog); });  // LOOK HERE
    buttonYesPopupRename.setStyle("-fx-text-fill:WHITE;-fx-background-color:#5264AE;-fx-font-size:14px;");

    JFXButton buttonNoPopupRename = new JFXButton("No");
    buttonNoPopupRename.setPrefHeight(30);
    buttonNoPopupRename.setPrefWidth(70);
    buttonNoPopupRename.setId("buttonNoPopupRename");
    buttonNoPopupRename.setButtonType(ButtonType.RAISED);
    buttonNoPopupRename.setOnAction(e -> { continuePopup.setValue(true); notifyPopup(dialog); });  // LOOK HERE
    buttonNoPopupRename.setStyle("-fx-text-fill:WHITE;-fx-background-color:#5264AE;-fx-font-size:14px;");

Answer 1

有比你的方法更好的解决问题的方法：

使有关需要询问的元素和当前元素的数据可供事件处理程序使用，并在事件发生时修改这些值和 UI。

让您为某些项目选择Yes 或No 的简化示例：

@Override
public void start(Stage primaryStage) {
    Button btn = new Button("Dialog");
    List<String> list = Arrays.asList("A", "B", "C", "D");
    btn.setOnAction((ActionEvent event) -> {
        displayDialog(list.iterator());
    });

    StackPane root = new StackPane();
    root.getChildren().add(btn);

    Scene scene = new Scene(root);

    primaryStage.setScene(scene);
    primaryStage.show();
}

public static void displayDialog(Iterator<String> iterator) {
    if (iterator.hasNext()) {
        Button yes = new Button("Yes");
        Button no = new Button("No");
        Label text = new Label(iterator.next());
        Stage stage = new Stage();
        stage.setScene(new Scene(new VBox(text, yes, no)));
        EventHandler<ActionEvent> handler = evt -> {
            Labeled source = (Labeled) evt.getSource();
            System.out.println("You chose \"" + source.getText() + "\" for \"" + text.getText() + "\"");

            // procede to next state
            if (iterator.hasNext()) {
                // display next item
                text.setText(iterator.next());
            } else {
                // close "dialog" when no more elements available
                stage.close();
            }
        };
        yes.setOnAction(handler);
        no.setOnAction(handler);
        stage.show();
    }
}

Answer 2

您必须在同步块中嵌入等待和通知：

synchronized( dialog)
{
    dialog.wait();
}

和

synchronized( dialog)
{
    dialog.notify();
}

顺便说一句：只需要 notify() 就足够了。只有当有多个线程在等待时，notifyAll(() 才有意义。