Starting services

Sometimes, we have to execute a task that must continue to run even if the user switches to another app or activity.

How to do it...

To be able to execute a task, even if the user switches away, we use a Service instance:

1. First, we need an instance of Service, and in most cases, we can use an IntentService instance:

   [Service]
   public class XamarinService : IntentService {
     protected override void OnHandleIntent(Intent intent) {
       // some long-running task
     }
   }

2. In order to begin execution, we invoke the StartService() method on the Context type:

   StartService(new Intent(this, typeof(XamarinService)));

3. We can pass data to the service when we start it by adding data to the intent:

   var intent = new Intent(this, typeof(XamarinService));
   intent.PutExtra("MyKey", "MyValue");
   StartService(intent);

4. Additionally, in the service, we can retrieve the values from the intent's extras:

   string value = null;
   if (intent.HasExtra("MyKey"))
     value = intent.GetStringExtra("MyKey");

How it works...

Some...