Prevent Orientation change in Xamarin Android Application

If you have an Activity, and you want to keep your activity in the same orientation when it is opened, then use this label:

[Activity(Label = "MyApp", ScreenOrientation = Android.Content.PM.ScreenOrientation.Locked)]

Set it in the Activity flag like this:

[Activity (Label = "YourActivityname", MainLauncher = true, ScreenOrientation = ScreenOrientation.Portrait)]