/// <summary>
/// Sets the ActiveMeasurement at the start of a measurement and casts BeginMeasurement events coming from a different thread to the UI thread when necessary.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="newMeasurement">The new measurement.</param>
/// <exception cref="System.NullReferenceException">Platform not set.</exception>
private void _comm_BeginMeasurement(object sender, ActiveMeasurement newMeasurement)
{
if (_platform == null)
{
throw new NullReferenceException("Platform not set.");
}
if (_platform.InvokeIfRequired(new CommManager.BeginMeasurementEventHandler(_comm_BeginMeasurement), sender, newMeasurement)) //Recast event to UI thread when necessary
{
return;
}
MeasurementStarted?.Invoke(this, EventArgs.Empty);
}
/// <summary>
/// Starts measurement process.
/// Sets values of fields and properties
/// responsible for the correct flow of the measurement process.
/// Invokes "MeasurementStarted" event.
/// Sets timer to let the application know
/// when the measurement process should be stopped automatically.
/// Executes the StartHeartRateMonitor method of the HeartRateMonitorModel object.
/// </summary>
private void StartMeasurement()
{
IsFinished = false;
IsMeasuring = true;
MeasurementCountdown = MEASUREMENT_TIME;
measurementStartTimestamp = DateTime.Now;
measurementValues = new List <int>();
MeasurementStarted?.Invoke(this, new EventArgs());
Device.StartTimer(TimeSpan.FromSeconds(MEASUREMENT_TIME), () =>
{
if (IsMeasuring && measurementLock == 0)
{
StopMeasurement();
((Command)ShowSettingsCommand).ChangeCanExecute();
}
if (measurementLock > 0)
{
measurementLock -= 1;
}
return(false);
});
Device.StartTimer(TimeSpan.FromSeconds(1), () =>
{
if (!IsMeasuring)
{
return(false);
}
TimeSpan measurementElapsedTime = DateTime.Now - measurementStartTimestamp;
MeasurementCountdown = MEASUREMENT_TIME - measurementElapsedTime.Seconds;
return(true);
});
heartRateMonitorModel.StartHeartRateMonitor();
}
/// <summary>
/// 测量开始事件
/// </summary>
protected void OnMeasurementStarted()
{
CanMeasure = false;
MeasurementStarted?.Invoke(this, new EventArgs());
}