Middleware in .net core not working, letting me step into it

Question

I was realizing that I need to write some middleware for httpcontext etc.., but thus I tried to take even an example from Microsoft, and the problem is that even with breakpoints on the outside ... app.Use and app.Run , with F11 it will not step into the code.

How can I even step into this code to see the values?

startup.cs file

public void Configure(IApplicationBuilder app)
{

    var request = new Request("api/menu/create", Method.POST);
    request.AddParameter("currentApplicationId", 1, ParameterType.QueryString);


    app.UseHttpsRedirection();
    app.UseStaticFiles();
    app.UseCookiePolicy();
    // UPDATE :  Code above prevented from being able to step into below?  

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

    app.Use((context, next) =>
    {
        var cultureQuery = context.Request.Query["culture"];
        if (!string.IsNullOrWhiteSpace(cultureQuery))
        {
            var culture = new CultureInfo(cultureQuery);
            CultureInfo.CurrentCulture = culture;
            CultureInfo.CurrentUICulture = culture;
        }

        // Call the next delegate/middleware in the pipeline
        return next();
    });

    app.Run(async (context) =>
    {
        await context.Response.WriteAsync(
        $"Hello {CultureInfo.CurrentCulture.DisplayName}");
    });

}

Franke

Which line of code do you want to step into? Put a breakpoint on it? – Pedicab

I debugged the code you placed and breakpoints hit on both middlewares, What's wrong? – Sentient

I put breakpoint on app.use and app.run and inside both of them and running the application it hits the outside but NEVER goes inside – Franke

put your breakpoint inside app.Use or app.Run not outside – Exoteric

I have put the breakpoints inside, it never hits them – Franke

@ChadJacobs Only thing I found wrong is that it should be next() instead of return next(); Please give a try with that and let me know. – Cappuccino

Oh, let me edit question, some of these other lines of code seem to prevented from entering? hang on while I post and update with code that was above it. – Franke

@ChadJacobs See my previous comment and check. – Cappuccino

Another wrong app.UseMvc should be the last middleware in the pipeline. Please also update this and give a try. – Cappuccino

I showed the code the is BEFORE , notice the // comment Update - I moved it back down and sure enough the code will not run . Lost as to which line is the reason why – Franke

Let us continue this discussion in chat. – Cappuccino

Tried the Chat, its blocked at my job /work – Franke

Ok, so app.UseMVC should be moved to last lines... – Franke

Yes, confirmed that I had to move the app.UseMvc(.. to be last . Thanks – Franke

Has it worked for you? and moreover have you replaced return next() with next()? – Cappuccino

It works with moving app.UseMvc under... It does not work with next , complains about needing a return on the lambda => – Franke

Okay! With return has it worked? – Cappuccino

Yes, thank you very much – Franke

Welcome! I have posted it as answer. Please check it. – Cappuccino

Answer 1

In ASP.NET Core request processing pipeline app.UseMvc() should be the last Middleware as follows, otherwise next middlewares would not call.

app.Use((context, next) =>
{
    var cultureQuery = context.Request.Query["culture"];
    if (!string.IsNullOrWhiteSpace(cultureQuery))
    {
        var culture = new CultureInfo(cultureQuery);
        CultureInfo.CurrentCulture = culture;
        CultureInfo.CurrentUICulture = culture;
    }

    // Call the next delegate/middleware in the pipeline
    return next();
});

app.Run(async (context) =>
{
    await context.Response.WriteAsync(
    $"Hello {CultureInfo.CurrentCulture.DisplayName}");
});

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

Hope it will solve your problem.

Cappuccino

Answer 2

Please use adding middleware in the mid or beginning

//Add our new middleware to the pipeline
app.UseMiddleware();

app.UseSwagger();

Eulaliaeulaliah

Welcome to StackOverflow! Please add some explanation why do you think your proposed solution might help the OP. – Equilibrant

I was creating middleware to authenticate bearer tokens and this comment helped me. I had my middle ware DI at the end and it was never called to authenticate tokens. – Hypaesthesia