活动识别API

Question

在最近的Google Play服务更新中，有人对活动识别API有问题吗？

我已经在一个应用程序中实现了它。在5.0更新之前，它工作得非常好。现在，当用户走路或坐着不动时，它会在车内返回：/

并且根本不返回WALING、RUNning或ON_FOOT。

我应该知道的活动识别API是否有任何更改？

如果你需要更多的细节，请告诉我。

Answer 1

您可以尝试这个简单的“for循环”，以确保您的用户正在驾驶。

for (DetectedActivity detectedActivity : detectedActivityList)
        {
           {
              if(DetectedActivity == “In_Vehicle” && result.getConfidence()> 75)
                     {
                        // output = User is Driving;
                        // Perform task 
                     }
           }
        }

请记住，要让Google Play services确保您的用户正在执行某项任务，置信度必须大于75，只有这样您才能确保任务已执行。或者，您可以尝试一些免费SDK，如Tranql、Neura或ContextHub，它们可以让您更好地了解用户的活动和位置。

Answer 2

主要的变化是ON_FOOT现在返回检测到的活动列表。现在改用getMostProbable活动（）。

此解决方案在步行时可以行走或跑步获取检测到的活动列表，如下所示：

//Get the list from the result
ActivityRecognitionResult result = ActivityRecognitionResult.extractResult(intent);
ArrayList<DetectedActivity> activityList = new ArrayList<DetectedActivity>(result.getProbableActivities());

//Get the most probable activity
getMostProbableActivity(activityList);

现在通过您的列表找到最可能的活动，如下所示：

private DetectedActivity getMostProbableActivity(List<DetectedActivity> detectedActivityList)
{
DetectedActivity result = null;

//Find the most probably activity in the list
for(DetectedActivity detectedActivity : detectedActivityList)
{
    if(detectedActivity.getType() != DetectedActivity.ON_FOOT)
    {
        if(result == null)
        {
            result = detectedActivity;
        }
        else
        {
            if(result.getConfidence() < detectedActivity.getConfidence())
            {
                result = detectedActivity;
            }
        }
    }
}

return result;

}

Answer 3

行走和跑步活动作为次要活动出现在列表中（ActivityRecognitionResult.getProbableActivities（）），您需要将它们解析出来。

// Get the update
ActivityRecognitionResult result = ActivityRecognitionResult.extractResult(intent);

// Get the most probable activity from the list of activities in the update
DetectedActivity mostProbableActivity = result.getMostProbableActivity();

// Get the type of activity
int activityType = mostProbableActivity.getType();

if (activityType == DetectedActivity.ON_FOOT) {
    DetectedActivity betterActivity = walkingOrRunning(result.getProbableActivities());
    if (null != betterActivity)
        mostProbableActivity = betterActivity;
}

private DetectedActivity walkingOrRunning(List<DetectedActivity> probableActivities) {
    DetectedActivity myActivity = null;
    int confidence = 0;
    for (DetectedActivity activity : probableActivities) {
        if (activity.getType() != DetectedActivity.RUNNING && activity.getType() != DetectedActivity.WALKING)
            continue;

        if (activity.getConfidence() > confidence)
            myActivity = activity;
    }

    return myActivity;
}

今天晚上我测试了上面的代码，包括步行和跑步，它看起来做得相当好。如果您不明确地只过滤RUN或WALING，您可能会得到错误的结果。

下面是处理新活动结果的完整方法。我直接从示例应用程序中提取了这个，并且已经测试了几天，结果很好。

/**
 * Called when a new activity detection update is available.
 */
@Override
protected void onHandleIntent(Intent intent) {
    Log.d(TAG, "onHandleIntent");

    // Get a handle to the repository
    mPrefs = getApplicationContext().getSharedPreferences(
            Constants.SHARED_PREFERENCES, Context.MODE_PRIVATE);

    // Get a date formatter, and catch errors in the returned timestamp
    try {
        mDateFormat = (SimpleDateFormat) DateFormat.getDateTimeInstance();
    } catch (Exception e) {
        Log.e(TAG, getString(R.string.date_format_error));
    }

    // Format the timestamp according to the pattern, then localize the pattern
    mDateFormat.applyPattern(DATE_FORMAT_PATTERN);
    mDateFormat.applyLocalizedPattern(mDateFormat.toLocalizedPattern());

    // If the intent contains an update
    if (ActivityRecognitionResult.hasResult(intent)) {

        // Get the update
        ActivityRecognitionResult result = ActivityRecognitionResult.extractResult(intent);

        // Log the update
        logActivityRecognitionResult(result);

        // Get the most probable activity from the list of activities in the update
        DetectedActivity mostProbableActivity = result.getMostProbableActivity();

        // Get the confidence percentage for the most probable activity
        int confidence = mostProbableActivity.getConfidence();

        // Get the type of activity
        int activityType = mostProbableActivity.getType();
        mostProbableActivity.getVersionCode();

        Log.d(TAG, "acitivty: " + getNameFromType(activityType));

        if (confidence >= 50) {
            String mode = getNameFromType(activityType);

            if (activityType == DetectedActivity.ON_FOOT) {
                DetectedActivity betterActivity = walkingOrRunning(result.getProbableActivities());

                if (null != betterActivity)
                    mode = getNameFromType(betterActivity.getType());
            }

            sendNotification(mode);
        }
    }
}

private DetectedActivity walkingOrRunning(List<DetectedActivity> probableActivities) {
    DetectedActivity myActivity = null;
    int confidence = 0;
    for (DetectedActivity activity : probableActivities) {
        if (activity.getType() != DetectedActivity.RUNNING && activity.getType() != DetectedActivity.WALKING)
            continue;

        if (activity.getConfidence() > confidence)
            myActivity = activity;
    }

    return myActivity;
}

/**
 * Map detected activity types to strings
 *
 * @param activityType The detected activity type
 * @return A user-readable name for the type
 */
private String getNameFromType(int activityType) {
    switch (activityType) {
        case DetectedActivity.IN_VEHICLE:
            return "in_vehicle";
        case DetectedActivity.ON_BICYCLE:
            return RIDE;
        case DetectedActivity.RUNNING:
            return RUN;
        case DetectedActivity.WALKING:
            return "walking";
        case DetectedActivity.ON_FOOT:
            return "on_foot";
        case DetectedActivity.STILL:
            return "still";
        case DetectedActivity.TILTING:
            return "tilting";
        default:
            return "unknown";
    }
}