岩心运动转换距离为公里

Question

在我的健康应用程序中，它表示距离为0，1公里，但在我的应用程序中，它给我的值为0.106。我怎么才能把这个变成一个忧郁呢？这是我用来获取当前统计数据的代码：

pedometer.queryPedometerData(from: Date().startOfDay, to: Date()) { data, error in
            guard let activityData = data, error == nil else {
                print("There was an error getting the data: \(String(describing: error))")
                return
            }
            print((Double(activityData.distance!.intValue)/Double(1000))) // Print out optional distance in of walking and running in meters. / 1000 to convert from meter to km.
        }

打印给我: 0.106

Answer 1

您可以使用Swift度量类型来转换您的长度单位，并使用MeasurementFormatter将其显示给用户：

let number: NSNumber = 106
let measurement = Measurement(value: number.doubleValue, unit: UnitLength.meters).converted(to: .kilometers)

let mf = MeasurementFormatter()
mf.unitOptions = .providedUnit
mf.unitStyle = .medium
mf.numberFormatter.maximumFractionDigits = 1
mf.string(from: measurement)   // "0.1 km"

就你而言：

guard let value = activityData.distance?.doubleValue else { return }
let measurement = Measurement(value: value, unit: UnitLength.meters).converted(to: .kilometers)

let mf = MeasurementFormatter()
mf.unitOptions = .providedUnit
mf.unitStyle = .medium
mf.numberFormatter.maximumFractionDigits = 1
mf.string(from: measurement)   // "0.1 km"

Answer 2

类似于：

let dist = Double(activityData.distance!.intValue)/Double(1000)
let str = String(format: @"%.1f", "", dist)
print(str)