Windows Phone 8.1, accelerometer gives wrong reading

Question

I am developing application for windows phone 8.1 and need to detect phone movement.

For example, I need to detect one of two scenarios:

User leans phone down

and user leans phone up

And here is the screenshot of application showing acelerometer readings when the phone is in position like on the second picture.

X-Axis, Y-Axis and Z-Axis are same (Same on my device). In the second picture when phone is facing up, X = -0.5317. Looks like that for some reason all axis take this value.

Here is the code.

public RoundPage()
{
    this.InitializeComponent();

    // ...

    this._accelerometer = Accelerometer.GetDefault();
    this._accelerometer.ReadingChanged += _accelerometer_ReadingChanged;
}

async void _accelerometer_ReadingChanged(Accelerometer sender, AccelerometerReadingChangedEventArgs args)
{
    double xAxis = args.Reading.AccelerationX;
    double yAxis = args.Reading.AccelerationY;
    double zAxis = args.Reading.AccelerationZ;

    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
        {
            AccTextBlock.Text = String.Format("X: {0:f2}  Y: {0:f2}  Z: {0:f2}",
                xAxis,
                yAxis,
                zAxis);
        });
}

What am I doing wrong? What is correct way do detect this readings.

Answer 1

我在String.Format方法中出错，我一直在打印xAxis（{0}）。