DeviceInformation.CreateFromIdAsync(deviceId) crashed

Question

DeviceInformation.CreateFromIdAsync(deviceId) crashed

longevity uyl 285

The following code crashed when deviceId="BluetoothLE#BluetoothLEd8:f8:83:9f:72:1a-c4:4d:87:46:02:3a"

DeviceInformation deviceInfo = await DeviceInformation.CreateFromIdAsync(deviceId);

And I get deviceId from member function GetId() of Device class. Do you have suggestion to fix this issue?

internal abstract class Device

{

    private readonly Windows.Devices.Enumeration.DeviceInformation info;

    protected abstract bool IsConnected { get; }

    public ConnectionStatus ConnectionStatus =>

        IsConnected

            ? ConnectionStatus.Connected

            : PairingInfo.IsPaired

                ? ConnectionStatus.Paired

                : ConnectionStatus.NotPaired;

    public Windows.Devices.Enumeration.DeviceInformationPairing PairingInfo => info.Pairing;

    public DeviceInfoId Id { get; }

    public string Name => info.Name;

    protected Device(Windows.Devices.Enumeration.DeviceInformation info)

    {

        this.info = info;

        Id = new DeviceInfoId(info);

    }

    public string GetId() {

        return info.Id;

    }

    public override string ToString()

    {

        return $"name:'{Name}' mac:'{Id.DeviceMac}' type:'{Id.DeviceType}' ConnectionStatus:'{ConnectionStatus}'";

    }

}

Anonymous

2023-11-07T09:56:42.3666667+00:00

Hi @longevity uyl , Welcome to Microsoft Q&A,

What error did you encounter specifically? Are you using any third party device?
longevity uyl 285 Reputation points

2023-11-07T10:50:34.6833333+00:00

Log messages before calling DeviceInformation deviceInfo = await DeviceInformation.CreateFromIdAsync(deviceid) can be printed. But log messages after calling this function cannot be printed. I just use Bluetooth device provided by Acer laptop. Do you have any suggestions to debug this issue?
Anonymous

2023-11-07T13:15:15.4266667+00:00

Hi @longevity uyl ,

You can wrap it with try catch and then use debugging breakpoints to view the error bit by bit.

Add error handling correctly.

longevity uyl 285

Thanks for your reply! Please refer to the following code. "1" has been printed. But "1.1" and "Error:" are not printed. Does it means exception handler is not called?

public static class Nus {
    private static readonly Guid NordicUartServiceUuid          = Guid.Parse("6e400001-b5a3-f393-e0a9-e50e24dcca9e");
    private static readonly Guid NordicUartTxCharacteristicUuid = Guid.Parse("6e400002-b5a3-f393-e0a9-e50e24dcca9e");
    private static readonly Guid NordicUartRxCharacteristicUuid = Guid.Parse("6e400003-b5a3-f393-e0a9-e50e24dcca9e");
 
    public static async Task<bool> SendMessage(string deviceId, string message) {
        try {
            Console.WriteLine("1");
            DeviceInformation deviceInfo = await DeviceInformation.CreateFromIdAsync(deviceId);
            Console.WriteLine("1.1");
            if (deviceInfo == null) {
                Console.WriteLine("Device not found.");
                return false;
            }

            Console.WriteLine("2");
            BluetoothLEDevice bluetoothLeDevice = await BluetoothLEDevice.FromIdAsync(deviceInfo.Id);
            if (bluetoothLeDevice == null) {
                Console.WriteLine("Failed to connect to the device.");
                return false;
            }

            Console.WriteLine("3");
            GattDeviceServicesResult servicesResult = await bluetoothLeDevice.GetGattServicesAsync();
            if (servicesResult.Status != GattCommunicationStatus.Success) {
                Console.WriteLine("Failed to retrieve GATT services.");
                return false;
            }

            Console.WriteLine("4");
            GattDeviceService nordicUartService = servicesResult.Services.FirstOrDefault(
                service => service.Uuid == NordicUartServiceUuid);
            if (nordicUartService == null) {
                Console.WriteLine("Nordic UART service not found.");
                return false;
            }

            Console.WriteLine("5");
            GattCharacteristicsResult characteristicsResult = await nordicUartService.GetCharacteristicsAsync();
            if (characteristicsResult.Status != GattCommunicationStatus.Success)
            {
                Console.WriteLine("Failed to retrieve characteristics of Nordic UART service.");
                return false;
            }

            Console.WriteLine("6");
            GattCharacteristic txCharacteristic = characteristicsResult.Characteristics.FirstOrDefault(
                characteristic => characteristic.Uuid == NordicUartTxCharacteristicUuid);
            if (txCharacteristic == null)
            {
                Console.WriteLine("Nordic UART TX characteristic not found.");
                return false;
            }

            Console.WriteLine("7");
            var writer = new DataWriter();
            writer.WriteString(message);
 
            GattCommunicationStatus writeStatus = await txCharacteristic.WriteValueAsync(writer.DetachBuffer());
            if (writeStatus == GattCommunicationStatus.Success)
            {
                Console.WriteLine("Message sent successfully.");
            }
            else
            {
                Console.WriteLine("Failed to send message.");
            }

            Console.WriteLine("8");
            return true;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error: {ex.Message}");
            return false;
        }
    }
}

Anonymous

2023-11-09T09:56:55.7033333+00:00
Hi @longevity uyl ,

Your code looks like it already uses exception handling (try-catch blocks) and prints an error message when an exception is caught. Judging from the information you provided, error messages should indeed be printed, including the error messages after "1.1".

Please ensure that no other exceptions are swallowed where await is called (for example, before GetGattServicesAsync() and GetCharacteristicsAsync() are called), otherwise the exception may be lost.

You can also use ex.ToString() in the catch block to print the complete exception stack information to better understand the problem. For example:

catch (Exception ex) { Console.WriteLine($"Error: {ex.ToString()}"); return false; }

This will print out detailed exception information including exception type, message and stack trace. This way you can more easily find the problem.