You defined your config structure in appsetings.json file, and you what to access this data in a Controller in your ASP.NET MVC or WebAPI project based on .NET Core 2.0. There are a couple of options, but one of the easiest is that.
The example structure of your configuration in appsetings.json file is below.
appsetings.json
[js]{"MySection": {
"MyFirstConfig": "Secret string",
"MySecondConfig": {
"MyFirstSubConfig": true,
"MySecondSubConfig": 32
}
}
}[/js]
Using built-in support for Dependency Injection, you can inject configuration data to Controller. Use AddSingleton method to add a singleton service in Startup.cs file. Just add services.AddSingleton(Configuration); in ConfigureServices.
Startup.cs
[csharp]public void ConfigureServices(IServiceCollection services){
services.AddMvc();
services.AddSingleton<IConfiguration>(Configuration);
}[/csharp]
In your Controller declare IConfiguration variable, and assign configuration in a constructor. To retrieve configuration data at Controller use:
_configuration["MySection:MyFirstConfig"](each configuration key separated by “:”) or_configuration.GetSection("MySection").GetSection("MySecondConfig").GetSection("MyFirstSubConfig")(each configuration key parsed by GetSection method) or_configuration.GetSection("MySection")["MySecondConfig:MySecondSubConfig"](mixed version – GetSection method with you section name as variable, and next configuration keys separated by “:” as Index).
Do not forget about using Microsoft.Extensions.Configuration; at the beginning 😉
HomeController.cs
[csharp]using Microsoft.AspNetCore.Mvc;using Microsoft.Extensions.Configuration;
namespace WebApplication1.Controllers
{
public class HomeController : Controller
{
private IConfiguration _configuration;
public HomeController(IConfiguration Configuration)
{
_configuration = Configuration;
}
public IActionResult Index()
{
// Read configuration using Key string
ViewData["MySectionMyFirstConfig"] = _configuration["MySection:MyFirstConfig"];
// Read configuration using GetSection method
ViewData["MySectionMySecondConfigMyFirstSubConfig"] = _configuration.GetSection("MySection").GetSection("MySecondConfig").GetSection("MyFirstSubConfig");
// Read configuration using mixed options with GetSection method and Key string
ViewData["MySectionMySecondConfigMySecondSubConfig"] = _configuration.GetSection("MySection")["MySecondConfig:MySecondSubConfig"];
return View();
}
}
}[/csharp]
Example output:
Index.cshtml
[html]<p>MySectionMyFirstConfig <strong>@ViewData["MySectionMyFirstConfig"]</strong><br />
MySectionMySecondConfigMyFirstSubConfig <strong>@ViewData["MySectionMySecondConfigMyFirstSubConfig"]</strong><br />
MySectionMySecondConfigMySecondSubConfig <strong>@ViewData["MySectionMySecondConfigMySecondSubConfig"]</strong>
</p>[/html]
Source code with this example you can find on my GitHub account: https://github.com/DariuszPorowski/CodeSamples/tree/master/DotNetCore20Config