Get Heart Rate From Microsoft Band

Question

I am trying to get the heart rate from a Microsoft Band. It should be updating whenever the value changes. I am then trying to display that value in a TextBlock. I first create an instance of IBandClient, and set its HeartRate.ReadingChanged method like this:

bandClient.SensorManager.HeartRate.ReadingChanged += HeartRate_ReadingChanged;

Then I try to update the value like this:

private void HeartRate_ReadingChanged(object sender, Microsoft.Band.Sensors.BandSensorReadingEventArgs<Microsoft.Band.Sensors.IBandHeartRateReading> e)
{
    HeartRate = e.SensorReading.HeartRate;
}

HeartRate is an int set like so:

public int HeartRate
{
    get { return (int)GetValue(HeartRateProperty); }
    set { SetValue(HeartRateProperty, value); }
}

// Using a DependencyProperty as the backing store for HeartRate.  This enables animation, styling, binding, etc...
public static readonly DependencyProperty HeartRateProperty =
    DependencyProperty.Register("HeartRate", typeof(int), typeof(MainPage), new PropertyMetadata(0));

The TextBlock text is then bound to HeartRate. However, I keep getting this error when trying to set HeartRate:

The application called an interface that was marshalled for a different thread. (Exception from HRESULT: 0x8001010E (RPC_E_WRONG_THREAD))

My guess is that it's trying to set HeartRate while it is still being set from the call before.

Do you know if the SensorManager is dispatching the event from another thread? That would mean you're trying to set your TextBlock text from a different thread than the UI thread, which you can't do (hence the error). — y2bd

Eugen Sunic Eugen Sunic · Accepted Answer · 2015-07-04T01:15:53

Try to implement this and see how it goes, if you still want your int variable, then convert it back to string when displaying it in a text-block.

await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, 
               () => 
               {
                   Textblock.Text =  e.SensorReading.HeartRate.ToString())
               }).AsTask();

Get Heart Rate From Microsoft Band

1 Answers