Read Values from AppSettings.json File

On the Visual Studio, select Create a new project from Get Started

Select ASP.NET Core Web Application

Input Project Name and select Location for new project

Select ASP.NET Core 5.0 Version and select ASP.NET Core Empty Template. Click Create button to finish

Open Startup.cs file and add new configurations as below:

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace LearnASPNETCoreMVC5
{
    public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllersWithViews();
        }

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

            app.UseRouting();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllerRoute(
                    name: "default",
                    pattern: "{controller=Demo}/{action=Index}/{id?}");
            });
        }
    }
}

Select Project and right click to select Add\New Item Menu

Select Web\ASP.NET in left side. Select App Settings File item and click Add button to Finish

In appsettings.json file and new configurations as below:

{
  "Message": "Hello World",
  "MyConfigs": {
    "Config1": "Value of Config 1",
    "Config2": "Value of Config 2",
    "Config3": "Value of Config 3"
  },
  "Logging": {
    "IncludeScopes": false,
    "Debug": {
      "LogLevel": {
        "Default": "Information"
      }
    }
  }
}

Create new folder named Controllers. In this folder, create new controller named DemoController.cs as below:

using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;

namespace LearnASPNETCoreMVC5.Controllers
{
    [Route("demo")]
    public class DemoController : Controller
    {
        private IConfiguration configuration;

        public DemoController(IConfiguration _configuration)
        {
            configuration = _configuration;
        }

        [Route("index")]
        [Route("")]
        [Route("~/")]
        public IActionResult Index()
        {
            ViewBag.result1 = configuration["Message"];
            ViewBag.result2 = configuration["MyConfigs:Config1"];
            ViewBag.result3 = configuration["MyConfigs:Config2"];
            ViewBag.result4 = configuration["MyConfigs:Config3"];
            ViewBag.result5 = configuration["Logging:Debug:LogLevel:Default"];
            return View();
        }
    }
}

Create new folder named Views. In this folder, create new folder named Demo. Create new view named Index.cshtml as below:

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
</head>
<body>

    Result 1: @ViewBag.result1
    <br />
    Result 2: @ViewBag.result2
    <br />
    Result 3: @ViewBag.result3
    <br />
    Result 4: @ViewBag.result4
    <br />
    Result 5: @ViewBag.result5

</body>
</html>

Access Index action in Demo controller with following url: http://localhost:48982/Demo/Index

Output

Create ASP.NET Core MVC 5 Project

Add Configurations

Create AppSettings File

Create Controller

Create View

Structure of ASP.NET Core MVC 5 Project

Run Application