Google fitness sensors: onDataPoint not being called

问题

I'm creating an app that tracks a user's steps using the google fit API. I've been stuck on getting the onDataPoint method to be called more than once. My code is almost the exact copy of the google-fit sample code, except with location replaced by steps.

The sample code is found here. It's very similar to the code I am testing out with, with a small adjustment.

Here is my code. Any help would be greatly appreciated, I looked all over and couldn't find a solution.

private void findFitnessDataSources() {
    // [START find_data_sources]
    // Note: Fitness.SensorsApi.findDataSources() requires the ACCESS_FINE_LOCATION permission.
    Fitness.SensorsApi.findDataSources(mClient, new DataSourcesRequest.Builder()
            // At least one datatype must be specified.
            .setDataTypes(DataType.TYPE_STEP_COUNT_DELTA)
            // Can specify whether data type is raw or derived.
            .setDataSourceTypes(DataSource.TYPE_RAW)
            .build())
            .setResultCallback(new ResultCallback<DataSourcesResult>() {
                @Override
                public void onResult(DataSourcesResult dataSourcesResult) {
                    Log.i(TAG, "Result: " + dataSourcesResult.getStatus().toString());
                    for (DataSource dataSource : dataSourcesResult.getDataSources()) {
                        Log.i(TAG, "Data source found: " + dataSource.toString());
                        Log.i(TAG, "Data Source type: " + dataSource.getDataType().getName());

                        //Let's register a listener to receive Activity data!
                        if (dataSource.getDataType().equals(DataType.TYPE_STEP_COUNT_DELTA)
                                && mListener == null) {
                            Log.i(TAG, "Data source for LOCATION_SAMPLE found!  Registering.");
                            registerFitnessDataListener(dataSource,
                                    DataType.TYPE_STEP_COUNT_DELTA);
                        }
                    }
                }
            });
}


private void registerFitnessDataListener(DataSource dataSource, DataType dataType) {
    // [START register_data_listener]
    mListener = new OnDataPointListener() {
        @Override
        public void onDataPoint(DataPoint dataPoint) {
            for (Field field : dataPoint.getDataType().getFields()) {
                Value val = dataPoint.getValue(field);
                Log.i(TAG, "Detected DataPoint field: " + field.getName());
                Log.i(TAG, "Detected DataPoint value: " + val);
            }
        }
    };

    Fitness.SensorsApi.add(
            mClient,
            new SensorRequest.Builder()
                    .setDataSource(dataSource) // Optional but recommended for custom data sets.
                    .setDataType(dataType) // Can't be omitted.
                    .setSamplingRate(1, TimeUnit.SECONDS)
                    .build(),
            mListener)
            .setResultCallback(new ResultCallback<Status>() {
                @Override
                public void onResult(Status status) {
                    if (status.isSuccess()) {
                        Log.i(TAG, "Listener registered!");
                    } else {
                        Log.i(TAG, "Listener not registered.");
                    }
                }
            });
}

回答1:

Issue was solved in a later SO question and my suspicion was correct. The issue is that TYPE_STEP_COUNT_DELTA is not a raw data type—Google uses a combination of sensors, accelerometer, machine learning, etc. to determine step count. So the .setDataSourceTypes(DataSource.TYPE_RAW) line needs to be removed.

In fact, the OP of the other question noticed that just removing the line gives less accurate results than replacing it with DataSource.TYPE_DERIVED, so that is advised.

回答2:

As i mentioned in my post that step_count of google fit uses derived datatype for everything whether It is cumulative,delta etc. I observed the results of my app for 10 iteration. I found that

Google fit API which is provided by google only uses derived datatype for all step_count.
You can also not specify the datatype ,but it can give variation in result when compared with Google Fit app.

The same thing is mentioned in Google Fit faq section. [https://developers.google.com/fit/faq

来源：https://stackoverflow.com/questions/38799685/google-fitness-sensors-ondatapoint-not-being-called

标签

android

google-fit