UWP Webview and Token Authorization

Andrey K.1 Thanks for the feedback! I've sent this to the team to get the examples updated, but I can't offer a timeline for that.

It seems that using a custom URL scheme with the PKCE flow works though. I don't have an official example to offer, but while I'm not a UWP programmer myself, it looks like the necessary pieces work in my testing. For instance:

First, I define a redirect URI using a custom URI scheme:

private readonly Uri RedirectUri = new Uri("customappurl://redirect_receiver/");

The "customappurl" is just an example. You should use something unique and specific to your app instead. The "redirect_receiver" can also be whatever you want.

Then I register that custom URI scheme in the UWP app as covered in Microsoft's 'Handle URI activation' documentation, and the redirect URI for the Dropbox API app on the Dropbox App Console.

Then I can configure the PKCE flow otherwise as shown in the existing example and get the authorization URL and launch that authorization URL in the system browser as shown in the Microsoft 'Launch the default app for a URI' documentation:

var OAuthFlow = new PKCEOAuthFlow();
var authorizeUri = OAuthFlow.GetAuthorizeUri(OAuthResponseType.Code, ApiKey, RedirectUri.ToString(), state: state, tokenAccessType: TokenAccessType.Offline, scopeList: scopeList, includeGrantedScopes: includeGrantedScopes);

var success = await Windows.System.Launcher.LaunchUriAsync(authorizeUri);
if (success)
{
    // URI launched
    System.Diagnostics.Debug.WriteLine("Launching authorize URI succeeded.");
}
else
{
    // URI launch failed
    System.Diagnostics.Debug.WriteLine("Launching authorize URI failed.");
}

That opens the authorization page in the system browser, and after the user authorizes the app, I can receive the resulting redirected URI as eventArgs.Uri in OnActivated per the Microsoft 'Handle URI activation' documentation. That should be passed to ProcessCodeFlowAsync like redirectUri is in the existing example.

Hope this helps!