java - 在按钮单击内显示加载 GIF，并在执行操作后再次隐藏它

Question

我有以下 JFrame，里面有一个足够简单的退出应用程序方法。我正在尝试添加某种加载程序(最好是旋转 GIF)。然而，目前我刚刚添加了一个名为“loading”的 JLabel，以便在单击按钮时显示文本“loading...”。

问题是消息框(即操作)在我的函数中根本不显示，并且加载 JLabel 继续显示。谁能解释一下为什么这不起作用，并给我关于如何用 GIF 替换加载文本的建议。任何帮助都会很棒。

 public void Exit() {
    btnExit.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent event) {
            // event start
            loading.setVisible(true);

            new SwingWorker<Void, String>() {
                @Override
                protected Void doInBackground() throws Exception {
                    Thread.sleep(100);
                    return null;
                }

                @Override
                protected void done() {
                    // event start
                    loading.setVisible(false);

                    // prompt user input message box //
                    int close = JOptionPane.showConfirmDialog(panel,"Are you sure?",
                            "Information", JOptionPane.YES_NO_OPTION);

                    // await user selection.
                    if(close == JOptionPane.YES_OPTION) {
                        System.exit(0);
                    }
                }
            };
        }
    });
}

Answer 1

创建 SwingWorker 本身是不够的。您必须调用其 execute()创建后的方法。

Schedules this SwingWorker for execution on a worker thread. There are a number of worker threads available. In the event all worker threads are busy handling other SwingWorkers this SwingWorker is placed in a waiting queue.

Note: SwingWorker is only designed to be executed once. Executing a SwingWorker more than once will not result in invoking the doInBackground method twice.

就您而言:

SwingWorker<?,?> worker = new SwingWorker<Void, String>() {
    @Override
    protected Void doInBackground() throws Exception {
        Thread.sleep(100);
        return null;
    }

    @Override
    protected void done() {
        // event start
        loading.setVisible(false);

        // prompt user input message box //
        int close = JOptionPane.showConfirmDialog(panel,"Are you sure?",
                "Information", JOptionPane.YES_NO_OPTION);

        // await user selection.
        if(close == JOptionPane.YES_OPTION) {
            System.exit(0);
        }
    }
};
worker.execute(); //Execute the worker