如何从服务回调到活动 [英] How to make a callback from a Service to an Activity

问题描述

对不起，再缠着你，但我仍然无法找到一种方法，使我从一个活动回调服务...

Sorry for bugging you again, but I still can't find a way to make a callback from my activity to a service...

发现了类似的问题？ - 如何在Android中定义回调

Found a similar question - How to Define Callbacks in Android?

// The callback interface
interface MyCallback {
    void callbackCall();
}

// The class that takes the callback
class Worker {
   MyCallback callback;

   void onEvent() {
      callback.callbackCall();
   }
}

// Option 1:

class Callback implements MyCallback {
   void callback() {
      // callback code goes here
   }
}

worker.callback = new Callback();

但不知道如何该样本融入我的项目。

yet not sure how to integrate that sample into my project.

任何建议或链接来清除教程将是巨大的！

Any suggestions or links to clear tutorials would be great!

推荐答案

这样的回调（Observer模式），您都出现在你的例子不会在服务和活动之​​间的合作。使用时，从A级，您创建实例B类并想送选自B回调到A观察者拍打。

That kind of callbacks (Observer pattern) that you are showing in your example won't work between a service and an activity. Use observer patter when, from class A, you created the instance of class B and want to send callbacks from B to A.

至于服务和活动，事情就完全不同了。 AFAICT，如果你要回拨你的活动从服务，实现这一目标的最好方法是使用<一个HREF =htt​​p://developer.android.com/reference/android/os/ResultReceiver.html相对=nofollow> ResultReceiver 。有一个关于很多有趣的事 ResultReceiver ：

With regards to the services and activities, things are completely different. AFAICT, if you want to callback your Activity from a Service, the best method to achieve this is to use ResultReceiver. There are a lot of interesting things about ResultReceiver:

• 它的构造函数接收一个 处理程序 （你必须在活动中创建），这将允许您从服务更改UI。


• 它实现 Parcelable 因此你可以把一个参考你的 ResultReceiver 在你用来启动服务意图演员


• 及其的onReceive 方法有一个结果code整数使您可以生成不同类型的回调（这就像如果你的回调接口有许多方法）。此外，它收到 捆绑 ，你可以用它来把所有结果数据。

• Its constructor receives a Handler (that you must create inside the activity), which will allow you to change UI from the service.
• It implements Parcelable thus you can put a reference of your ResultReceiver in the Intent extras that you used to start the service.
• Its onReceive method has a result code integer which allows you to generate different kind of callbacks (this is like if your callback interface had many methods). Also, it receives a Bundle which you can use to put all result data.

在另一方面，如果你想要做一个的回调的（不知道这是在这种情况下，正确的术语），从你的活动你的服务，我想你将不得不发送广播消息或类似的东西。

On the other hand, if you want to do a callback (not sure if that is correct term in this case), from your Activity to your Service, I guess you will have to send a Broadcast message or something like that.

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