android - FileObserver 不起作用

Question

在我的 Android 应用程序中，我想检测目录中的事件。这是代码:

String path = Environment.getExternalStorageDirectory()
            + File.separator + "test2";
    Log.d("test", "path is " + path);

    FileObserver fileObserver = new FileObserver(path, FileObserver.ALL_EVENTS) {
        @Override
        public void onEvent(int event, String path) {
            Log.d("test", "event dectect " + event + " " + path);
        }
    };

    fileObserver.startWatching();

我将新文件复制到目录中。但我没有得到任何事件。请告诉我哪里出错了。

Answer 1

您不能使用局部变量来存储您的 FileObserver，它在方法运行后可用于垃圾回收。

Warning: If a FileObserver is garbage collected, it will stop sending events. To ensure you keep receiving events, you must keep a reference to the FileObserver instance from some other live object.

解决办法:保存到字段中。