How to read connection string in .NET Core?

Question

I want to read just a connection string from a configuration file and for this add a file with the name "appsettings.json" to my project and add this content on it:

{
"ConnectionStrings": {
  "DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=aspnet-

 WebApplica71d622;Trusted_Connection=True;MultipleActiveResultSets=true"
  },
    "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
    "Default": "Debug",
    "System": "Information",
    "Microsoft": "Information"
   }
 }
}

On ASP.NET I used this:

 var temp=ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;

Now how can I read "DefaultConnection" in C# and store it on a string variable in .NET Core?

Answer 1

The posted answer is fine but didn't directly answer the same question I had about reading in a connection string. Through much searching I found a slightly simpler way of doing this.

In Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    ...
    // Add the whole configuration object here.
    services.AddSingleton<IConfiguration>(Configuration);
}

In your controller add a field for the configuration and a parameter for it on a constructor

private readonly IConfiguration configuration;

public HomeController(IConfiguration config) 
{
    configuration = config;
}

Now later in your view code you can access it like:

connectionString = configuration.GetConnectionString("DefaultConnection");