.NetCore SignalR CORS is not allowing client calls

Question

In my .Netcore application I am using SingalR to pass messages to different clients

My code is like this

      services.AddCors( options =>
                          {
                              options.AddPolicy( "mypolicy", builder =>
                                                 {
                                                     builder.AllowAnyHeader();
                                                     builder.AllowAnyMethod();
                                                     builder.AllowAnyOrigin();
                                                     builder.AllowCredentials();
                                                 } );
                          } );

        services.AddMvc();
        services.Configure<MvcOptions>( options => { options.Filters.Add( new CorsAuthorizationFilterFactory( "mypolicy" ) ); } );
        services.Configure<SignalROptions>( options => options.Hubs.EnableDetailedErrors = true );

My .Netcore application is running here http://localhost:88 and I am accessing it through http://localhost

If I try to use

        builder.WithOrigins("http://localhost");

I am able to access the SignalR services. My problem is I will be accessing the .NetCore application from different clients that means from different client domains so it is not practically possible to add all those clients in WithOrgins.

So builder.AllowAnyOrigin(); is the best solution for me.

Can anyone tell me how to achieve it.

Answer 1

You should call app.UseCors() method which applies CORS policies to all the apps endpoints via CORS Middleware.

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    if (env.IsDevelopment())
    {
       app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseHsts();
    }

    app.UseCors(); 

    app.UseHttpsRedirection();
    app.UseMvc();
}

more about cors you can find here