Xamarin Mobile Development for Android Cookbook

Listening for sensor triggers

Some sensors do not provide a continuous stream of data, but rather raise an event when something happens.

How to do it...

To use trigger-based sensors, we also make use of the sensor manager. Unlike stream-based sensors, we inherit from the TriggerEventListener type:

1. First, we need the instance of the SensorManager type:

   var manager = SensorManager.FromContext(this);

2. Next, we get a reference to the sensor. If the sensor is null, then it is not available on the device:

   var type = SensorType.SignificantMotion;
   var motion = manager.GetDefaultSensor(type);
   if (motion == null) {
     // handle no significant motion sensor
   }

3. Then, we create inherit from the TriggerEventListener type:

   private class MyListener : TriggerEventListener ...