android - Activity 转换 API 不起作用

Question

我希望使用新的 Activity 转换 API 并遵循教程 here我无法得到想要的结果。

这是我用于设置我希望检测的 Activity 转换的代码:

public void setActivityTransitions() {
    transitionList = new ArrayList<>();
    ArrayList<Integer> activities = new ArrayList<>(Arrays.asList(
            DetectedActivity.STILL,
            DetectedActivity.WALKING,
            DetectedActivity.ON_FOOT,
            DetectedActivity.RUNNING,
            DetectedActivity.ON_BICYCLE,
            DetectedActivity.IN_VEHICLE));
    for (int activity :
            activities) {
        transitionList.add(new ActivityTransition.Builder()
                .setActivityType(activity)
                .setActivityTransition(ActivityTransition.ACTIVITY_TRANSITION_ENTER).build());

        transitionList.add(new ActivityTransition.Builder()
                .setActivityType(activity)
                .setActivityTransition(ActivityTransition.ACTIVITY_TRANSITION_EXIT).build());

    }

}

然后请求 Activity 转换更新:

 ActivityTransitionRequest activityTransitionRequest = new ActivityTransitionRequest(transitionList);
        Intent intent = new Intent(context, ActivityDetectorTransitionService.class);
        intent.setAction("com.test.activityrecognition.START_ACTIVITY_TRANSITION_DETECTION_ALARM");
        PendingIntent pendingIntent = PendingIntent.getService(context, 1, intent, PendingIntent.FLAG_UPDATE_CURRENT);
        Task<Void> task = ActivityRecognition.getClient(context).requestActivityTransitionUpdates(activityTransitionRequest, pendingIntent);
        task.addOnSuccessListener(new OnSuccessListener<Void>() {
            @Override
            public void onSuccess(Void result) {
                System.out.println("onSuccess");
            }
        });
        task.addOnFailureListener(new OnFailureListener() {
            @Override
            public void onFailure(@NonNull Exception e) {
                e.printStackTrace();
                System.out.println("onFailure");
            }
        });

这是广播接收器:

    public class ActivityDetectorTransitionService extends BroadcastReceiver {
    private static final String TAG = "ActivityDetectorTransitionService";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (ActivityTransitionResult.hasResult(intent)) {
            ActivityTransitionResult activityTransitionResult = ActivityTransitionResult.extractResult(intent);
            ActivityDetectorTransitionAPI.getInstance().handleActivityRecognitionResult(activityTransitionResult);
        }
    }
}

(该名称中包含服务，因为最初我保留了它的服务但仍然无法正常工作。)

并在 list 中:

<receiver
    android:name=".tracking.activityrecognition.ActivityDetectorTransitionService">
    <intent-filter>
        <action android:name="com.test.activityrecognition.START_ACTIVITY_TRANSITION_DETECTION_ALARM"/>
    </intent-filter>
</receiver>

Answer 1

您正在使用 PendingIntent.getService()结合 BroadcastReceiver .

使用 BroadcastReceiver 接收待处理的 Intent 您必须检索 PendingIntent使用 PendingIntent.getBroadcast() 的实例.可以找到有关 Intent 和 Intent 过滤器的相应开发人员指南 here .

从 Android 8 开始有几个 background service limitations .使用 IntentService仅在应用程序处于前台时有效。要在应用程序关闭后接收 Activity 转换更新，您甚至必须使用 BroadcastReceiver .为此，BroadcastReceiver正如 Jan Maděra 已经提到的，必须在具有相应权限的应用程序 list 中注册。

   <receiver android:name="com.mypackage.ActivityTransitionBroadcastReceiver"
       android:exported="false"
       android:permission="com.google.android.gms.permission.ACTIVITY_RECOGNITION">
       <intent-filter>
           <action android:name="com.mypackage.ACTION_PROCESS_ACTIVITY_TRANSITIONS" />
       </intent-filter>
   </receiver>

此外 onReceive()应该只响应您的具体操作，因为 intent filters are not guaranteed to be exclusive .

public class ActivityTransitionBroadcastReceiver extends BroadcastReceiver {

    public static final String INTENT_ACTION = "com.mypackage" +
                    ".ACTION_PROCESS_ACTIVITY_TRANSITIONS";

    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent != null && INTENT_ACTION.equals(intent.getAction())) {
            if (ActivityTransitionResult.hasResult(intent)) {
                ActivityTransitionResult intentResult = ActivityTransitionResult
                        .extractResult(intent);
                // handle activity transition result ...
            }
        }
    }
}

使用 PendingIntent.getBroadcast() 请求 Activity 转换更新:

ActivityTransitionRequest request = new ActivityTransitionRequest(transitionList);

Intent intent = new Intent(context, ActivityTransitionBroadcastReceiver.class);
intent.setAction(ActivityTransitionBroadcastReceiver.INTENT_ACTION);

PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0, intent,
        PendingIntent.FLAG_UPDATE_CURRENT);

Task<Void> task = ActivityRecognition.getClient(context)
        .requestActivityTransitionUpdates(request, pendingIntent);

请注意， Activity 转换更新可能会延迟接收。这取决于设备，也可能受电源管理限制的影响。