Maui Blazor hybrid - White screen on AbpInitialization #9883

5 Answer(s)

• 

  0

  AI-Bot created yesterday

  Support Team ABP Agent

  • To handle network failures during ABP module initialization in a MAUI Blazor Hybrid app (especially on Samsung devices with aggressive battery optimization), you should implement a more resilient initialization and error handling strategy. The ABP initialization process expects a successful remote configuration fetch; if the network is unavailable (as with Samsung's battery optimization), it will throw an exception and show a white screen.

  • Here are recommended approaches:

  1. Graceful Network Failure Handling

     • Wrap the ABP initialization (especially the call to MauiBlazorCachedApplicationConfigurationClient.InitializeAsync()) in a try-catch block.
     • If a network error occurs, display a user-friendly message or a retry button, rather than allowing the app to crash or hang on a white screen.
     • Optionally, implement a retry/backoff policy using Polly, but ensure you do not block the UI thread or create an infinite loop.

  2. Defer or Skip Configuration Refresh

     • On app resume, check for network connectivity before attempting to refresh the configuration.
     • If the network is unavailable, skip the refresh and allow the app to use cached configuration, if available.
     • You can use Xamarin.Essentials/MAUI Essentials Connectivity.NetworkAccess to check network status.

     Example:

  if (Connectivity.NetworkAccess == NetworkAccess.Internet)
     {
         await MauiBlazorCachedApplicationConfigurationClient.InitializeAsync();
     }
     else
     {
         // Show offline message or use cached data
     }
  

  3. Custom Error UI

     • Implement a fallback UI for initialization errors. For example, show a dialog with "Retry" and "Exit" options if initialization fails due to network issues.

  4. Samsung Battery Optimization Guidance

     • Inform users about battery optimization issues and provide instructions to whitelist your app in Samsung's battery settings.
     • You can direct users to: Settings > Apps > [Your App] > Battery > Unrestricted.

  5. Avoid Using "localhost" in Production

     • The error Unable to resolve host "localhost" suggests the app is trying to connect to a local server, which will not work on a physical device. Ensure your RemoteService:BaseUrl and OIDC Authority point to a reachable server, not localhost.

  6. Polly Integration

     • ABP supports Polly for retry logic on HTTP client proxies. However, this does not help if the network is completely unavailable or if the device is blocking all requests. Use Polly for transient errors, but always check for connectivity first.

     Reference: ABP Polly Integration

  7. Session Persistence

     • Ensure your authentication/session tokens are persisted securely so that the user does not need to re-login after a failed resume.

  By combining these strategies, you can provide a much better user experience and avoid white screens or crashes due to Samsung's battery optimization.

  Sources:

  • ABP Polly Integration

  ---

  This response was generated by AI. If it didn’t solve your problem, feel free to post a new answer — our support team will jump in to help you soon.

  Save Cancel
• 

  0

  aziz.bouhejba created yesterday

  Tried all of these solutions, the only one we didn't try is // Show offline message or use cached data

  Save Cancel
• 

  0

  maliming created yesterday

  Support Team Fullstack Developer

  hi

  The app needs to retrieve remote data (MauiBlazorCachedApplicationConfigurationClient) during startup.

  Unable to resolve host "localhost": No address associated with hostname

  This seems to be a DNS problem.

  Can you try to override the MauiBlazorCachedApplicationConfigurationClient service to catch the exception and try again?

  https://github.com/abpframework/abp/blob/e6a51b14104fc9a8a95406e93397160873e306b6/framework/src/Volo.Abp.AspNetCore.Components.MauiBlazor/Volo/Abp/AspNetCore/Components/MauiBlazor/MauiBlazorCachedApplicationConfigurationClient.cs#L56-L91

  Thanks.

  Save Cancel
• 

  0

  aziz.bouhejba created 10 hours ago

  Hi thanks, we ended up waiting for internet connection to come back, it's definitely killed by some Samsung devices when battery is optimized so the ABP apps crashes for them because of the network dependency. This was our solution

  using Microsoft.Extensions.Configuration;
  using Volo.Abp;
  
  namespace SampleProject.MauiBlazor;
  
  public partial class App : Application
  {
      private readonly IServiceProvider serviceProvider;
      private Page? rootPage;
  
      public App(IServiceProvider serviceProvider)
      {
          InitializeComponent();
          this.serviceProvider = serviceProvider;
          UserAppTheme = AppTheme.Light;
      }
  
      protected override Window CreateWindow(IActivationState? activationState)
      {
          rootPage = new MainPage();
  
          var window = new Window(rootPage);
  
          // Initialize asynchronously without blocking
          _ = Task.Run(async () =>
          {
              try
              {
                  await WaitForNetworkConnectivityAsync();
                  serviceProvider.GetRequiredService<IAbpApplicationWithExternalServiceProvider>().Initialize(serviceProvider);
  
                  // Switch to main page on UI thread
                  MainThread.BeginInvokeOnMainThread(() =>
                  {
                      window.Page = new MainPage();
                  });
              }
              catch (Exception ex)
              {
                  rootPage = new MainPage();
              }
          });
  
          return window;
      }
  
      private static async Task WaitForNetworkConnectivityAsync()
      {
          var connectivity = Connectivity.Current;
          var maxRetries = 30; // 30 seconds max wait
          var retryCount = 0;
  
          while (retryCount < maxRetries)
          {
              if (connectivity.NetworkAccess == NetworkAccess.Internet)
              {
                  if (await CanReachApiAsync())
                  {
                      return;
                  }
              }
  
              await Task.Delay(1000); // Wait 1 second
              retryCount++;
          }
  
          // Log warning or show user message about connectivity issues
          System.Diagnostics.Debug.WriteLine("Network connectivity timeout");
      }
  
      private static async Task<bool> CanReachApiAsync()
      {
          try
          {
              using var client = new HttpClient { Timeout = TimeSpan.FromSeconds(5) };
              var response = await client.GetAsync("https://google.com");
              return response.IsSuccessStatusCode;
          }
          catch
          {
              return false;
          }
      }
  }
  
  

  I would recommend having something like this in the template because all Samsung devices will fail with an ABP template. we struggled with this issue for months because not everyone was able to reproduce it. 😬

  Thanks again have a good day

  Save Cancel

  1
• 

  0

  maliming created 10 hours ago

  Support Team Fullstack Developer

  Great solution. Thanks 👍

  Save Cancel