SimpleOrientationSensor.OrientationChanged | orientationchanged event

function onOrientationChanged(eventArgs) { /* Your code */ }
 
// addEventListener syntax
simpleOrientationSensor.addEventListener("orientationchanged", onOrientationChanged);
simpleOrientationSensor.removeEventListener("orientationchanged", onOrientationChanged);
 
- or -

simpleOrientationSensor.onorientationchanged = onOrientationChanged;

private void ScenarioEnable(object sender, RoutedEventArgs e)
{
    if (_sensor != null)
    {
        Window.Current.VisibilityChanged += new WindowVisibilityChangedEventHandler(VisibilityChanged);
        _sensor.OrientationChanged += new TypedEventHandler<SimpleOrientationSensor, SimpleOrientationSensorOrientationChangedEventArgs>(OrientationChanged);

        ScenarioEnableButton.IsEnabled = false;
        ScenarioDisableButton.IsEnabled = true;

        // Display the current orientation once while waiting for the next orientation change
        DisplayOrientation(ScenarioOutput_Orientation, _sensor.GetCurrentOrientation());
    }
    else
    {
        rootPage.NotifyUser("No simple orientation sensor found", NotifyType.StatusMessage);
    }
}

async private void OrientationChanged(object sender, SimpleOrientationSensorOrientationChangedEventArgs e)
{
    await Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
    {
        DisplayOrientation(ScenarioOutput_Orientation, e.Orientation);
    });
}

private void DisplayOrientation(TextBlock tb, SimpleOrientation orientation)
{
    switch (orientation)
    {
        case SimpleOrientation.NotRotated:
            tb.Text = "Not Rotated";
            break;
        case SimpleOrientation.Rotated90DegreesCounterclockwise:
            tb.Text = "Rotated 90 Degrees Counterclockwise";
            break;
        case SimpleOrientation.Rotated180DegreesCounterclockwise:
            tb.Text = "Rotated 180 Degrees Counterclockwise";
            break;
        case SimpleOrientation.Rotated270DegreesCounterclockwise:
            tb.Text = "Rotated 270 Degrees Counterclockwise";
            break;
        case SimpleOrientation.Faceup:
            tb.Text = "Faceup";
            break;
        case SimpleOrientation.Facedown:
            tb.Text = "Facedown";
            break;
        default:
            tb.Text = "Unknown orientation";
            break;
    }
}

function enableReadingChangedScenario() {
    if (sensor) {
        document.addEventListener("msvisibilitychange", msVisibilityChangeHandler, false);
        sensor.addEventListener("orientationchanged", onDataChanged);
        document.getElementById("scenario1Open").disabled = true;
        document.getElementById("scenario1Revoke").disabled = false;
    } else {
        WinJS.log && WinJS.log("No simple orientation sensor found", "sample", "error");
    }
}

function onDataChanged(e) {
    switch (e.orientation) {
        case Windows.Devices.Sensors.SimpleOrientation.notRotated:
            document.getElementById("eventOutputOrientation").innerHTML = "Not Rotated";
            break;
        case Windows.Devices.Sensors.SimpleOrientation.rotated90DegreesCounterclockwise:
            document.getElementById("eventOutputOrientation").innerHTML = "Rotated 90";
            break;
        case Windows.Devices.Sensors.SimpleOrientation.rotated180DegreesCounterclockwise:
            document.getElementById("eventOutputOrientation").innerHTML = "Rotated 180";
            break;
        case Windows.Devices.Sensors.SimpleOrientation.rotated270DegreesCounterclockwise:
            document.getElementById("eventOutputOrientation").innerHTML = "Rotated 270";
            break;
        case Windows.Devices.Sensors.SimpleOrientation.faceup:
            document.getElementById("eventOutputOrientation").innerHTML = "Face Up";
            break;
        case Windows.Devices.Sensors.SimpleOrientation.facedown:
            document.getElementById("eventOutputOrientation").innerHTML = "Face Down";
            break;
        default:
            document.getElementById("eventOutputOrientation").innerHTML = "Undefined orientation " + e.orientation;
            break;
    }
}