Blazor WebAssembly Hosted app using Azure AD B2C - How to determine when the user clicked Cancel?

Question

I have a Blazor WebAssembly Hosted C# application (.NET 6.0) using Azure AD B2C. On the B2C login screen, if the user clicks Cancel for Forgot Password, Sign-Up or Create Account, B2C will redirect to /authentication/login-callback within the Blazor app. How can I determine whether the user clicked Cancel in B2C within Authentication.razor in the Blazor app? There are no query string values when /authentication/login-callback enters Authentication.razor. Also, /authentication/login-callback changes to /authentication/login-failed?message=AADB2C90091 in the browser but does not enter the OnInitializedAsync method in Authentication.razor.

Answer 1

The problem was solved by adding a Razor component and adding the component to the LogInFailed section of the Authentication.razor file. The LoginFailedRedirect.razor file redirects the user back to the Azure AD B2C login screen. Please see the details below.

Authentication.razor excerpt:
@Anonymous "/authentication/{action}"
@using Microsoft.AspNetCore.Components.WebAssembly.Authentication

<RemoteAuthenticatorView Action="@朱大星 " OnLogOutSucceeded=@this.OnLogOutSucceeded OnLogInSucceeded=@this.OnLogInSucceeded >
<LoggingIn>
<div>LoggingIn</div>
</LoggingIn>
<LogInFailed>
<LoginFailedRedirect />
</LogInFailed>
<LogOut>
<div>LogOut</div>
</LogOut>
</RemoteAuthenticatorView>

LoginFailedRedirect.razor:
@inject NavigationManager Navigation

@Aidan Wick {
protected override void OnInitialized()
{
Navigation.NavigateTo($"authentication/login");
}
}

A specific error code can be obtained from the message query string value in the LoginFailedRedirect.razor. Below is an example of the excerpt of the return URL from Azure AD B2C.
/authentication/login-failed?message=AADB2C90091%3A%20The%20user%20has%20cancelled%20entering%20self-asserted%20information.