Is it possible to allow detection of device orientation change for only one page

Question

My project is set to only allow portrait. But on one page, I want it to be able to detect user rotation of the device from either portrait to landscape, or from landscape and portrait, and then change the page's orientation correspondingly. I did some search, and found that I can use MessagingCenter to notify, for example, MainActivity in Android to change the orientation to the desired orientation. But that is still not what I want. That implementation is not able to detect user's rotation of the device.

Answer 1

Hello,​

Welcome to our Microsoft Q&A platform!

Is it possible to allow detection of device orientation change for only one page

If you set the ScreenOrientation = ScreenOrientation.Portrait in the MainActivity.cs to keep the only allow portrait. This answer is Yes

If you want to allow detection of device orientation change for only one page, You can an interface in PCL.

   public interface IDetectScreen  
       {  
           void EnableDetectOrientation();  
           void CloseDetectOrientation();  
       }  

Then achieve it in the Dependency service in android platform.

   [assembly: Xamarin.Forms.Dependency(typeof(DetectScreenService))]  
     
   namespace AudioDemo.Droid  
   {  
       class DetectScreenService : IDetectScreen  
       {  
           public void CloseDetectOrientation()  
           {  
               
               MainActivity.Intance.RequestedOrientation = Android.Content.PM.ScreenOrientation.Portrait;  
     
           }  
     
           public void EnableDetectOrientation()  
           {  
               MainActivity.Intance.RequestedOrientation = Android.Content.PM.ScreenOrientation.Sensor;  
     
           }  
       }  
   }  

MainActivity.Instance. is a public static value .

   public static MainActivity Instance;  
     
           protected override void OnCreate(Bundle savedInstanceState)  
           {  
               base.OnCreate(savedInstanceState);  
     
   //set the value to Intance   
     
               Instance= this;  
     
     
               Xamarin.Essentials.Platform.Init(this, savedInstanceState);  
               global::Xamarin.Forms.Forms.Init(this, savedInstanceState);  
               LoadApplication(new App());  
     
                
           }  

To use the above, subclass ContentPage and override the OnAppearing and OnDisappearing methods and subscribe to the DeviceDisplay.MainDisplayInfoChanged event to detect and test that the change occurred as in the following code sample:

   public partial class Page1 : ContentPage  
       {  
           public Page1()  
           {  
               InitializeComponent();  
     
               DeviceDisplay.MainDisplayInfoChanged += OnMainDisplayInfoChanged;  
     
           }  
           private void OnMainDisplayInfoChanged(object sender, DisplayInfoChangedEventArgs e)  
           {  
               var displayInfo = e.DisplayInfo;  
     
               var rotation = displayInfo.Rotation;  
               var displayOrientation = displayInfo.Orientation;  
     
     
               DisplayAlert("info", rotation + " " + displayOrientation, "OK");  
           }  
           protected override void OnAppearing()  
           {  
               base.OnAppearing();  
               DependencyService.Get<IDetectScreen>().EnableDetectOrientation();  
           }  
     
           protected override void OnDisappearing()  
           {  
               base.OnDisappearing();  
               DependencyService.Get<IDetectScreen>().CloseDetectOrientation();  
     
     
           }  
       }  

Best Regards,

Leon Lu

---

If the response is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.