线程任务完成后,JavaFX显示对话

Question

我需要显示对话窗口

 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();   

在我的线程完成任务之后

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

            });

我试过了

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();
    }

但这个应用程序没有响应,直到doSomeStuff()完成

Answer 1

t.join()是一个阻塞调用,因此它将阻止FX应用程序线程,直到后台线程完成.这将阻止重新绘制UI或响应用户输入.

做你想做的最简单的方法是使用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();

低级(即不使用高级API JavaFX提供)方法是从后台线程安排FX应用程序线程上的对话框显示:

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();

我强烈建议使用第一种方法.