線程任務完成后，JavaFX顯示對話

Question

我需要顯示對話窗口

 Stage dialog = new Stage();
            dialog.initStyle(StageStyle.UTILITY);
            Scene scene = new Scene(new Group(new Text(25, 25, "All is done!")));
            dialog.setScene(scene);
            dialog.showAndWait();   

我的線程完成任務后

Thread t = new Thread(new Runnable() {
                @Override
                public void run() {
                   doSomeStuff();
                }

            });

我試過了

Thread t = new Thread(new Runnable() {
            @Override
            public void run() {
                doSomeStuff();
            }

        });
        t.start();
        t.join();
        Stage dialog = new Stage();
        dialog.initStyle(StageStyle.UTILITY);
        Scene scene = new Scene(new Group(new Text(25, 25, "All is done!")));
        dialog.setScene(scene);
        dialog.showAndWait();
    }

但是直到doSomeStuff()完成后，此應用程序才響應

Answer 1

t.join()是一個阻塞調用，因此它將阻塞FX Application線程，直到后台線程完成。 這將防止重新粉刷UI或響應用戶輸入。

做您想做的最簡單的方法是使用Task ：

Task<Void> task = new Task<Void>() {
    @Override
    public Void call() throws Exception {
        doSomeStuff();
        return null ;
    }
};
task.setOnSucceeded(e -> {
    Stage dialog = new Stage();
    dialog.initStyle(StageStyle.UTILITY);
    Scene scene = new Scene(new Group(new Text(25, 25, "All is done!")));
    dialog.setScene(scene);
    dialog.showAndWait();
});
new Thread(task).start();

一種低級（即不使用JavaFX提供的高級API）方法是從后台線程安排對話框在FX Application線程上的顯示：

Thread t = new Thread(() -> {
    doSomeStuff();
    Platform.runLater(() -> {
        Stage dialog = new Stage();
        dialog.initStyle(StageStyle.UTILITY);
        Scene scene = new Scene(new Group(new Text(25, 25, "All is done!")));
        dialog.setScene(scene);
        dialog.showAndWait();
    });
});
t.start();

我強烈建議您使用第一種方法。