Swift - 无法检索CMSensorDataList记录

Question

我正在创建一个记录用户加速的Watch应用程序。我使用了CMSensorRecorder框架中的CoreMotion来做到这一点。

现在程序的流程是用户按下手表上的按钮，触发加速记录30秒。在此之后，有6分钟的延迟（参考这里的答案：watchOS2 - CMSensorRecorder，读取数据需要延迟），并且加速度和时间戳数据被打印到控制台。

现在，我在运行应用程序时收到“响应无效”和“发生错误”。我已经在info.plist文件中添加了动作用法说明。

我对Swift和应用程序开发很新，我担心我试图访问数据的方式有问题。我在下面附上了控制台日志和代码。

任何人都可以提供一些有关消息的见解以及如何解决这个问题？我已经四处搜索，但之前没有找到任何此类问题的案例。干杯。

    func recordAcceleration(){
        if CMSensorRecorder.isAccelerometerRecordingAvailable(){
            print("recorder started")
            recorder.recordAccelerometer(forDuration: 30)   //forDuration controls how many seconds data is recorded for.
            print("recording done")
        }
    }

    func getData(){
        if let list = recorder.accelerometerData(from: Date(timeIntervalSinceNow: -400), to: Date()){
            print("listing data")

            for data in list{
                if let accData = data as? CMRecordedAccelerometerData{
                    let accX = accData.acceleration.x
                    let timestamp = accData.startDate
                    //Do something here.
                    print(accX)
                    print(timestamp)
                }
            }
        }

    }


    //Send data to iphone after time period.
    func sendData(dataBlock:CMSensorDataList){
        WCSession.default.transferUserInfo(["Data" : dataBlock])
    }



    //UI Elements
    @IBAction func recordButtonPressed() {
        print("button pressed")
        recordAcceleration()

        //A delay is needed to read the data properly.
        print("delaying 6 mins")
        perform(#selector(callback), with: nil, afterDelay: 6*60)

    }

    @objc func callback(){
        getData()
    }

    extension CMSensorDataList: Sequence {
    public func makeIterator() -> NSFastEnumerationIterator {
        return NSFastEnumerationIterator(self)
    }

Console output:

button pressed

recorder started

2019-03-12 12:12:12.568962+1100 app_name WatchKit Extension[233:5614] [Motion] Warning - invoking recordDataType:forDuration: on main may lead to deadlock.

2019-03-12 12:12:13.102712+1100 app_name WatchKit Extension[233:5614] [SensorRecorder] Response invalid.

recording done

delaying 6 mins

2019-03-12 12:18:13.115955+1100 app_name WatchKit Extension[233:5614] [Motion] Warning - invoking sensorDataFromDate:toDate:forType: on main may lead to deadlock.

2019-03-12 12:18:13.162476+1100 app_name WatchKit Extension[233:5753] [SensorRecorder] Error occurred while trying to retrieve accelerometer records!

Answer 1

我运行了你的代码并没有得到“响应无效”或“发生错误”。我确实得到了主线程警告。所以我改为后台线程，它工作正常。

另外，我认为你不需要等待六分钟。我把它改成了一分钟。

我希望这有帮助。

let recorder = CMSensorRecorder()
@IBAction func recordAcceleration() {
    if CMSensorRecorder.isAccelerometerRecordingAvailable() {
        print("recorder started")
        DispatchQueue.global(qos: .background).async {
            self.recorder.recordAccelerometer(forDuration: 30)
        }
        perform(#selector(callback), with: nil, afterDelay: 1 * 60)
    }
}
@objc func callback(){
    DispatchQueue.global(qos: .background).async { self.getData() }
}
func getData(){
    print("getData started")
    if let list = recorder.accelerometerData(from: Date(timeIntervalSinceNow: -60), to: Date()) {
        print("listing data")
        for data in list{
            if let accData = data as? CMRecordedAccelerometerData{
                let accX = accData.acceleration.x
                let timestamp = accData.startDate
                //Do something here.
                print(accX)
                print(timestamp)
            }
        }
    }
}