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我的 android 应用程序必须与服务器通信。一个活动因此创建一个意图并启动一个 IntentService 派生。

按照一些提示，比如这个，我扩展了 ResultReceiver 来处理答案：我的活动实现了包含的 Receiver 接口（因此实现了 onReceiveResult）。

public class MyResultDistributor extends ResultReceiver {

// Class instances serves one purpose: To remember who gets the answer.
private Receiver mReceiver;

// Constructor: Apparently, the "handler" determines in which thread the result handling is done.
public MytResultDistributor(Handler handler) {
    super(handler);
}

// This is what the receiver of request answers has to implement.
public interface Receiver {
    public void onReceiveResult(int resultCode, Bundle resultData);
}

// Allows to clarify who is the receiver of request results.
public void setReceiver(Receiver receiver) {
    if (receiver != null) {
        Log.d(this.getClass().toString(), "Setting receiver.");
    } else {
        Log.d(this.getClass().toString(), "Unsetting receiver.");
    }
    this.mReceiver = receiver;
    if (this.mReceiver != null) {
        Log.d(this.getClass().toString(), "Set receiver.");
    } else {
        Log.d(this.getClass().toString(), "Unset receiver.");
    }
}

@Override
protected void onReceiveResult(int resultCode, Bundle resultData) {
    // Anybody interested in the results? Well, then feel free to take them.
    Log.d(this.getClass().toString(), "Got result.");
    if (this.mReceiver != null) {
        Log.d(this.getClass().toString(), "Distributing result.");
        this.mReceiver.onReceiveResult(resultCode, resultData);
    } else {
        Log.d(this.getClass().toString(), "No receiver there.");
    }
}

该活动创建了一个实例，并将自己设置为接收者（摘录）：

public class MainActivity extends Activity implements MyResultDistributor.Receiver {

public MyResultDistributor mDistributor;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    Log.v(this.getClass().toString(), "onCreate");
    setContentView(R.layout.activity_main);

    mDistributor = new MyResultDistributor(new Handler());
    mDistributor.setReceiver(this);

    (...)
}

@Override
protected void onPause() {
    super.onPause();
    Log.v(this.getClass().toString(), "onPause");
    mDistributor.setReceiver(null);
}

@Override
protected void onResume() {
    super.onResume();
    Log.v(this.getClass().toString(), "onResume");
    mDistributor.setReceiver(this);
}

(...)

现在，当我运行活动时，启动我的服务并返回结果，它似乎mReceiver为空。但我看不到它在日志中设置为 null 的位置！？？

日志摘录：

onCreate
Setting receiver.
Set receiver.
onResume
Setting receiver.
Set receiver.
Request Service was created.
Request Service has got an Intent.
Server answer: auth
Authenticated!
Got result.
No receiver there.

其中最后 5 条消息具有不同的 TID。

为什么接收器在一种方法中出现设置而在另一种方法中显示为未设置？我有线程问题吗？也许通过使用做错了new Handler()什么？

感谢您的任何提示！

4

1 回答 1

1

好的，我想我发现了我的错误：我以某种方式将错误的接收器传递给了我的 IntentService - 所以我正在观看的实例是不同的。抱歉这个无法解决的问题......（因为没有显示该代码部分。）。

于 2014-10-03T23:08:59.500 回答