Making phone calls

Our app may need to initiate a phone call from within the app without the user having to leave the current context.

How to do it...

To initiate a call directly from within our app, we use an Intent instance:

1. We first need to ensure that the device has telephony features. There are two ways to do this; one way is to use attributes:

   [assembly: UsesFeature(
     Android.Content.PM.PackageManager.FeatureTelephony)]

   Alternatively, we can check for the telephony feature using the HasSystemFeature() method at runtime:

   var hasTelephony = PackageManager.HasSystemFeature(
     Android.Content.PM.PackageManager.FeatureTelephony);
   if (hasTelephony) {
     // do something
   }

2. If we are running on a device with telephony features, we still need to request permissions to start phone calls:

   [assembly: UsesPermission(Manifest.Permission.CallPhone)]

3. Finally, we can make the phone call using the ActionCall action intent:

   var number = "0123456789";
   var intent = new Intent(Intent.ActionCall);
   intent.SetData(Uri...