how many InputFile components can I have in blazor

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• Bind Collections EF Core

  I am about to create a blazor application with ef core. I read the Microsoft recommentation about how to Setup EF Core DbContextFactory

  Until now i used in my Razor-Components bindindings to the DbSet like

  <select @bind-value="dbContext.People" />
  

  since I read the Article I'm a little confused of how to used it now, because they use the dbcontext inside of a using-Statement.

  because of the using statement i cant directly bind a dbset anymore???

  @inject IDbContextFactory<DatabaseContext> DbFactory
  
  <select @bind-value="dbContext.People" />
  
  @code
  {
      DatabaseContext dbContext;
  
      protected override Task OnInitializedAsync()
      {
          using var dbContext = DbFactory.CreateDbContext();
      }
  }
  

  Whats your suggestion for that?

  If i use

  <input @bind-value="People" />
  
  @code
  {
      ICollection<Person> People;
  
      protected override Task OnInitializedAsync()
      {
          using var dbContext = DbFactory.CreateDbContext();
          People = dbContext.People;
      }
  }
  

  nothing will be displayed. The Debugger tells me:

  Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances. Object name: 'DatabaseContext'.
• Blazor server side performance issues

  Its a Blazor server side project with about 100 .razor pages, When a change occurs on one of the pages, it takes about 19 seconds to rebuild pages, restart IIS Express and refresh the page. It's awful, I make only a minor change in html, but it takes long time to show the results. The test result is like this :
  
  

  With 100 razor pages and all css and js references
  build : 10 sec
  refresh page : 19 sec (include 10 secs for build)
  

  When we remove 90 pages of 100 pages (10 pages remains) :
  build : 3 sec
  refresh page : 12 sec (include 3 secs for build)
  

  When we remove all css and js references :
  build : 3 sec
  refresh page : 6 sec (include 3 secs for build)
  

  It is not good at all, because the project is growing and finally we will have about 400 pages! and extra css and js references will added. In this case, the time will be much longer for developing.
  

  

  what's the solution? Thanks
• Unable to create a Role using RoleManager in Blazor Serverside

  I had some code using the RoleManager that I had copied from an MVC project to create roles in a Blazor project. It compiles okay but when I step through the code it gets to that line and then appears to throw and exception, as it doesn't ever go to the next line. I am unable to catch an exception though.

  Since my code didn't work I found code on the web and it behaved the same, so I changed how it was injected and I got a different error, so I found a third way of doing it and that too gets to the line that tests to see if there is a role already existing and blows up.

  Here is the latest attempt

    [Inject]
      IServiceProvider services {get;set;}
      public async Task Initialize()
      {
          using (var roleManager = services.GetRequiredService<RoleManager<IdentityRole>>())
          {
              string proRole = "Pro";
             
              if (!await roleManager.RoleExistsAsync(proRole))
              {
                  var temp = await roleManager.CreateAsync(new IdentityRole { Name = proRole });
              }
              
          }
      }
  

  And it blows up on the awaited if statement.

  Here is the previous code that should work that doesn't.

   string proRole = "Pro";
                  string proClientRole = "ProClient";
                  if (!await _roleManager.RoleExistsAsync(proRole))
                  {
                      var temp = await _roleManager.CreateAsync(new IdentityRole { Name = proRole });
                  }
  

  which is inside of a method.

  I also had it as @{code in the Razor file and after an hour of trying different things there I moved it to a base class because they have been more stable in the past.

  It is not the database connection because that is well verified and also because UserManager is called in the same class and it work

  I also tried this code (Blazor Role Management Add Role trough UI (Crud)) both suggestions.

  This is one bad thing about Blazor for me is it is buggy I never know if it is my bad, or just something wrong with the latest greatest. But I am assuming it is my bad in this case.

  Anyway any help would be much appreciated, I am way too many hours on this,