Error while using Middleware

Question

I’m trying to use Middleware, so that every time a user logs into the system it is being redirected to condominium registration screen, he can not use the system until you register at least 1 condominium.

But I’m getting the following errors:

Code of my Middleware ~/Custom/Middleware/Redirectnocondominium.Cs

public class RedirectNoCondominium
{
    private readonly UserManager<ApplicationUsers> _userManager;
    private readonly ICondominiumService _condominiumManager;
    private readonly RequestDelegate _next;
    private readonly string path = "~/Condominium/Add";

    public RedirectNoCondominium(
        RequestDelegate next, 
        UserManager<ApplicationUsers> userManager,
        ICondominiumService condominiumManager)
    {
        _condominiumManager = condominiumManager;
        _userManager = userManager;
        _next = next;
    }

    public ClaimsPrincipal User { get; private set; }

    public async Task Invoke(HttpContext httpContext)
    {
        var user = await _userManager.GetUserAsync(User);

        List<ApplicationCondominium> result = await _condominiumManager.GetCondominiumAsync(user.Id);

        if (result.Count() == 0 && httpContext.Request.Path != path)
        {
            httpContext.Response.Redirect(path);
        }
        else
            await _next(httpContext);
    }
}

And here at my startup.Cs I make his call.

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        app.UseMiddleware<RedirectNoCondominium>(); <-- aqui

        app.UseForwardedHeaders();

        app.Use(async (context, next) =>
        {
            if (context.Request.IsHttps || context.Request.Headers["X-Forwarded-Proto"] == Uri.UriSchemeHttps)
            {
                await next();
            }
            else
            {
                string queryString = context.Request.QueryString.HasValue ? context.Request.QueryString.Value : string.Empty;
                var https = "https://" + context.Request.Host + context.Request.Path + queryString;
                context.Response.Redirect(https);
            }
        });


        if (env.IsDevelopment())
        {

            app.UseDeveloperExceptionPage();
            app.UseDatabaseErrorPage();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            app.UseHsts();
        }


        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy();

        app.UseAuthentication();

        app.UseNToastNotify();

        app.UseMvc(routes =>
        {
            routes.MapRoute(
                name: "default",
                template: "{controller=Home}/{action=Index}/{id?}");
        });
    }

Answer 1

The solution is to inject in the method invoke

public class RedirectNoCondominium
{    
    private readonly ICondominiumService _condominiumManager;
    private readonly RequestDelegate _next;
    private readonly string path = "~/Condominium/Add";

    public RedirectNoCondominium(
        RequestDelegate next,         
        ICondominiumService condominiumManager)
    {
        _condominiumManager = condominiumManager;        
        _next = next;
    }

    public ClaimsPrincipal User { get; private set; }

    public async Task Invoke(HttpContext httpContext,
                             UserManager<ApplicationUsers> userManager)
    {
        var user = await userManager.GetUserAsync(User);

        List<ApplicationCondominium> result = 
                await _condominiumManager.GetCondominiumAsync(user.Id);

        if (result.Count() == 0 && httpContext.Request.Path != path)
        {
            httpContext.Response.Redirect(path);
        }
        else
            await _next(httpContext);
    }
}

---

Note is that the same code, but, will depend on how you did in the Startup.cs, example:

It has to be configured in the Startup.cs in the method ConfigureServices:

services.AddDefaultIdentity<IdentityUser>()
    .AddDefaultUI(UIFramework.Bootstrap4)
    .AddEntityFrameworkStores<ApplicationDbContext>();

in the Configure method after app.UseAuthentication();, example:

app.UseAuthentication();
app.UseMiddleware<RedirectNoCondominium>();

In the method of middlweare thus:

public class RedirectNoCondominium
{        
    private readonly RequestDelegate _next;
    private readonly string path = "/Condominium/Add";

    public RedirectNoCondominium(RequestDelegate next)
    {            
        _next = next;
    }


    public async Task Invoke(HttpContext httpContext, 
                             UserManager<IdentityUser> userManager)
    {
        if (httpContext.User.Identity.IsAuthenticated)
        {
            IdentityUser user = 
                await userManager.GetUserAsync(httpContext.User);
            var id = user.Id; // Id do usuário
            //trabalhe pra frente o seu código ...
            if (user != null)
            {
                if (httpContext.Request.Path.Value != path)
                {
                    httpContext.Response.Redirect(path);
                }
                else
                {
                    await _next(httpContext);
                }
            }
            else
            {
                await _next(httpContext);
            }
        }
        else
        {
            await _next(httpContext);
        }
    }
}

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