UseExceptionHandler not routing unhandled exceptions to Error page-CodePudding

In my .Net Blazor server application I want an Error page to be shown to the user in case of unhandled exceptions. But I can't seem to get this error page shown. To try to get it shown I have added a button that simply throws an Exception (I have also tried forcing a DivideByZeroException), but instead of the UseExceptionHandler picking this up I just get an unhandled exception in my debug output (running it without debugging just freezes the page). My middleware configuring hierarchy seems to check out. If I just type in the url, localhost:[port]/Error, I get to the error page.

What am I missing?

Startup.cs

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseExceptionHandler("/Error");           
    app.UseHsts();
    app.UseHttpsRedirection();
    app.UseStaticFiles();
    app.UseRouting();
    app.UseEndpoints(endpoints =>
    {
        endpoints.MapBlazorHub();
        endpoints.MapFallbackToPage("/_Host");
    });
}

Error.cshtml

@page 
@model Presentation.WebUI.Pages.ErrorModel

<!DOCTYPE html>
<html>
[...html...]
</html>

Error.cshtml.cs

using [...]

namespace Presentation.WebUI.Pages
{
    [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
    [IgnoreAntiforgeryToken]
    public class ErrorModel : PageModel
    {
        public string RequestId { get; set; }

        public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);

        private readonly ILogger<ErrorModel> _logger;

        public ErrorModel(ILogger<ErrorModel> logger)
        {
            _logger = logger;
        }

        public void OnGet()
        {
            RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier;
        }
    }
}

CodePudding user response：

The solution was to replace the Error.cshtml and Error.cshtml.cs with a Blazor component (.razor) and add the below component structure to the MainLayout.cs-file:

<ErrorBoundary>
   <ChildContent>                      
      @Body                                
   </ChildContent>
   <ErrorContent Context="Exception">
      <Presentation.WebUI.Pages.Error></Presentation.WebUI.Pages.Error>
   </ErrorContent>
</ErrorBoundary>