android - 每 5 秒向 Web 服务发送一次请求

Question

我想监听 sql server 数据库以了解 android 中的数据是否有变化，所以我想每 5 秒向 web 服务发送一次请求以了解新的数据值。我该怎么做？你能举个例子吗？

Answer 1

你可以用 AsyncTask 来做，

public void callAsynchronousTask() {
    final Handler handler = new Handler();
    Timer timer = new Timer();
    TimerTask doAsynchronousTask = new TimerTask() {       
        @Override
        public void run() {
            handler.post(new Runnable() {
                public void run() {       
                    try {
                        PerformBackgroundTask performBackgroundTask = new PerformBackgroundTask();
                        // PerformBackgroundTask this class is the class that extends AsynchTask 
                        performBackgroundTask.execute();
                    } catch (Exception e) {
                        // TODO Auto-generated catch block
                    }
                }
            });
        }
    };
    timer.schedule(doAsynchronousTask, 0, 50000); //execute in every 50000 ms
}

更多:How to execute Async task repeatedly after fixed time intervals