Win10 IoT + RPI3 WiFiAdapter throws Access Denied

Question

Trying to use the WiFi Adapter on a Raspberry Pi 3, using Windows 10 IoT

Code I'm trying to run:

 private async Task<IEnumerable<string>> ScanNetworksAsync()
    {
        var access = await WiFiAdapter.RequestAccessAsync();

        if (access != WiFiAccessStatus.Allowed)
        {
            throw new Exception("Not Allowed to use WiFi");
        }

        var wifi = WiFiAdapter.FindAllAdaptersAsync().AsTask().Result[0];

        await wifi.ScanAsync();

        return wifi.NetworkReport.AvailableNetworks.Select(n => n.Ssid);
    }

I do have the capability defined in the Package.appxmanifest:

<DeviceCapability Name="wiFiControl" />

When it tries to execute wifi.ScanAsync(), it just throws this error:

Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

What am I missing or doing wrong?

Answer 1

Figured it out. It's something unclear or just missing from the documentation.

All the wifi commands such as ScanAsync() ConnectAsync() can not be run in the UI thread. I was running them in a separate thread, but I was still blocking the UI anyway (didn't care cause it's just a test app). Apparently that's not allowed.

I found a comment in the sample app:

        // RequestAccessAsync must have been called at least once by the app before using the API
        // Calling it multiple times is fine but not necessary
        // RequestAccessAsync must be called from the UI thread

Which implies RequestAccessAsync() only works if run in the UI thread. I tested it both ways, and it seems to work no matter where it's run.