Why PhoneLinetransportDevice throwing error?

Question

I'm using an API called PhoneLineTransportDevice to make an HFP and SCO connection between my windows and phone so that I can make and pick calls from my pc with a bluetooth connection

using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Windows.ApplicationModel.Calls;
 using Windows.Devices.Enumeration;
 
 namespace PhoneLinetransportdevice
 {
 internal class Program
     {
 static async Task Main(string[] args)
         {
 DeviceInformationCollection devices = await DeviceInformation.FindAllAsync(PhoneLineTransportDevice.GetDeviceSelector(PhoneLineTransport.Bluetooth));
 for (int i = 0; i < devices.Count; i++)
             {
 if (devices[i].Name== "OPPO F11 Pro")
                 {
 Console.WriteLine(i + "#:    " + devices[i].Name);
 var PDevice = PhoneLineTransportDevice.FromId(devices[i].Id);
 var result = await PDevice.RequestAccessAsync();
 if (!PDevice.IsRegistered())
                     {
 PDevice.RegisterApp();
                     }
 var flag = await PDevice.ConnectAsync();
 if (flag)
                     {
 Console.WriteLine("Connected");
                     }
 else
                     {
 Console.WriteLine("Could not connect to PhoneLineDevice");
                     }
                 }
             }
         }
     }
 }

var result = await PDevice.RequestAccessAsync(); giving denied by the system I get know that PhoneLineTransportdevice automatically make a HFP and SCO connection instead of creating an HFP connection first then SCO connection but this is giving error anyone know why? I have checked this API isnt depricated but still giving error

Unhandled Exception: System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)) at Windows.ApplicationModel.Calls.PhoneLineTransportDevice.RegisterApp() at PhoneLinetransportdevice.Program.d__0.MoveNext() in C:\StudioApps\PhoneLinetransportdevice\PhoneLinetransportdevice\Program.cs:line 25 --- End of stack trace from previous location where exception was thrown --- at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
at PhoneLinetransportdevice.Program.(String[] args)

Are you using Windows 11? Is it related to [this issue](https://github.com/BestOwl/MyPhone/issues/26)? — Abu Saad Papa, Apr 26 '23 at 08:55
i am using windows 11 and i dont know if its related to windows or my device @AbuSaadPapa — Aryaveer Chaudhary, Apr 26 '23 at 09:54
If you are using Windows 11 then it is related to the above issue. We need to find out if Microsoft has officially blocked this API from Windows 11 onwards. — Abu Saad Papa, Apr 26 '23 at 10:25
but in windows 10 the RequestAccessAsync results allowed but the app is not getting registered which results in connection failed. Means even after using PDevice.RegisterApp(); the app is still unregistered in windows 10 @AbuSaadPapa — Aryaveer Chaudhary, Apr 26 '23 at 10:32
and in docs its clearly there that this api supports build 22621 — Aryaveer Chaudhary, Apr 26 '23 at 10:36

score 0 · Accepted Answer · answered Apr 27 '23 at 10:27

0

I contacted Microsoft and they said they were not aware of this issue. After checking they said there is some permission issue with this API in Windows 11 and they will resolve it soon. We must wait for Microsoft to resolve this issue.

answered Apr 27 '23 at 10:27

Abu Saad Papa

1,908
15
20

when I run the same code in Windows 10 var result = await PDevice.RequestAccessAsync(); gives allowed but I am not able to register my app with PDevice.RegisterApp(); do you have any idea? – Aryaveer Chaudhary May 01 '23 at 05:20
Check this [app](https://github.com/BestOwl/MyPhone). It will be helpful to you. The app works in Windows 10. – Abu Saad Papa May 01 '23 at 11:51
for me its not working in windows 10 – Aryaveer Chaudhary May 02 '23 at 04:57
[Here](https://github.com/BestOwl/MyPhone/issues/26#issuecomment-1473975431) he is mentioning it is not working in windows 10. Please check if it is the same version as yours. – Abu Saad Papa May 02 '23 at 10:35

Why PhoneLinetransportDevice throwing error?

1 Answers1