Android的服务通知活动已完成最好的方法是什么？ [英] android service notify activity completed best way?

问题描述

我创建了同步数据在网络上的一个后台线程，并希望在该服务已完成，因此它可以更新它的指针通知列表活动服务？什么是做到这一点的最好方法是什么？我想发送一个广播的服务做，但不知道这是做到这一点的最好办法时。我需要重新查询光标时，该服务已经完成，所以我不知道这会工作以及与广播接收机？我没有提前做了很多的Andr​​oid在一段时间这样的感谢。

I created a service which syncs data from the web on a background thread and want to notify a list activity when the service has completed so it can update it's cursor? What would be the best way to do this? I'm thinking of sending a broadcast when the service is done but not sure if that's the best way to do it. I need to requery the cursor when the service has finished so I'm not sure if that will work well with broadcast receivers? I haven't done alot of android in awhile so thanks in advance.

推荐答案

使用处理程序在你的服务，注册了一个客户端，当你的 ListActivity 连接到服务;也就是说，在你的 ListActivity ，发送的留言 onServiceConnected 方法为您服务，让您跟踪连接的客户端。然后，你可以简单地通过服务于这些客户端的环，并给他们发送消息当事情发生在你的服务，你要通知你的 ListActivity 关于。欲了解更多信息，你可以看看code。在我的一个正在进行的项目：我的<一个href="https://github.com/zeitkunst/FluidNexusAndroid/blob/experimental/src/net/fluidnexus/FluidNexus/MainActivity.java"><$c$c>ListActivity和我的<一个href="https://github.com/zeitkunst/FluidNexusAndroid/blob/experimental/src/net/fluidnexus/FluidNexus/services/NetworkService.java"><$c$c>Service存根。

Use a Handler in your service that registers a client when your ListActivity connects to the service; that is, in your onServiceConnected method in your ListActivity, send a Message to your service that enables you to keep track of connected clients. Then you can simply loop through these clients in your Service and send them a Message when something takes place in your Service that you want to notify your ListActivity about. For more information you can look at code in an on-going project of mine: my ListActivity and my Service stub.

总之，在你的 MainActivity ，启动并绑定到你的服务有：

In short, in your MainActivity, start and bind to your service with:

Intent i = new Intent(this, NetworkService.class);
startService(i);
bindService(i, networkServiceConnection, Context.BIND_AUTO_CREATE);

定义使者从服务响应消息，如：

Define a messenger to respond to messages from the service like:

Messenger messenger = new Messenger(new IncomingHandler());

class IncomingHandler extends Handler {
    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case NetworkService.MSG_SOMETHING:
                // do something here
                break;
            default:
                super.handleMessage(msg);
        }
    }
}

，然后写你的服务连接code这样的：

And then write your service connection code like:

private ServiceConnection networkServiceConnection = new ServiceConnection() {
    public void onServiceConnected(ComponentName className, IBinder service) {
        networkService = new Messenger(service);
        try {
            Message msg = Message.obtain(null, NetworkService.MSG_REGISTER_CLIENT);
            msg.replyTo = messenger;
            networkService.send(msg);
            log.debug("Connected to service");

        } catch (RemoteException e) {
            // Here, the service has crashed even before we were able to connect
        }
    }

请注意，的replyTo 是我们刚创建的​​使者。

Note that the replyTo is the messenger we just created.

在你的网​​络服务，跟踪连接的客户端有：

In your NetworkService, keep track of connected clients with:

ArrayList<Messenger> clients = new ArrayList<Messenger>();

和创建的处理程序，如：

and create your handler like:

class IncomingHandler extends Handler {
       @Override
       public void handleMessage(Message msg) {
           switch (msg.what) {
               case MSG_REGISTER_CLIENT:
                   log.debug("Adding client: " + msg.replyTo);
                   clients.add(msg.replyTo);
                   break;
               default:
                   super.handleMessage(msg);
                   break;
           }
       }
   }

然后，当你想要发送一条信息给你的 MainActivity ，只是做类似如下：

Then, when you want to send a message back to your MainActivity, just do something like the following:

for (int i = 0; i < clients.size(); i++) {
    try {
        clients.get(i).send(Message.obtain(null, MSG_SOMETHING));
    } catch (RemoteException e) {
        // If we get here, the client is dead, and we should remove it from the list
        log.debug("Removing client: " + clients.get(i));
        clients.remove(i);
    }
}

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