Cross-thread operation exception when setting ownerWindow in PlatformParameters

[rhythmnewt]

Which Version of ADAL are you using ?
ADAL 3.18.0 and later

Which platform has the issue?
net462

What authentication flow has the issue?

• Desktop
  • [ X] Interactive

Other? - please describe;

Repro
Create new WinForms project targeting .NET 462 and add the following code to handle Load event.

   private async void Form1_Load(object sender, EventArgs e)
        {
            WindowState = FormWindowState.Normal;

            //fill in as necessary for correct auth
            const string resource = "https://www.myresource.com/";
            const string clientId = "client_id_guid";
            const string redirectUri = "https://myredirecturi";
            const string authority = "https://login.windows.net/myauthority/oauth2/token";

            var context = new AuthenticationContext(authority, true, TokenCache.DefaultShared);

            var result = await context.AcquireTokenAsync(resource, clientId,
                new Uri(redirectUri),
                new PlatformParameters(PromptBehavior.SelectAccount, this));
        }

Expected behavior
Windows form is shown in the background with the browser login window in the foreground. The browser login window is the child of the windows form.

Actual behavior
Exception is thrown:
System.InvalidOperationException: 'Cross-thread operation not valid: Control 'Form1' accessed from a thread other than the thread it was created on.'

Possible Solution

Additional context/ Logs / Screenshots
WindowsFormsApp1.zip

If you downgrade the library to 3.17.3 there is no issue with the cross-threading.

[rhythmnewt]

Bueller?

[MarkZuber]

@rhythmnewt

Still investigating. But I have a short term workaround that should hopefully get you unblocked.

When you construct the PlatformParameters, send in "null" instead of "this" for the owner window. The owner window is only used for trying to center the browser around the owner app window. If it's null, then the browser will be centered on the current screen. That should be the only difference in functionality and I'll get back to this thread once I've gotten deeper on the issue with ownerWindow.

[MarkZuber]

Pull request for fix is out: #1328

[henrik-me]

fixed in https://github.com/AzureAD/azure-activedirectory-library-for-dotnet/releases/tag/ADAL-v4.3.0

[henrik-me]

This has now been released

[rhythmnewt]

@MarkZuber the issue was around the modality of the window, don't want the user to click in the app screen while the login flow is active.

Thank you all for taking care of it!