无法从appsettings.json获取连接字符串

Question

I'm building my own API web app using ASP.NET Core 2.0. But I cannot get my connection string stored in appsettings.json .

Here is my code in the Startup.cs file, the connection variable holds the connection string, but somehow it is always null:

public void ConfigureServices(IServiceCollection services) {
   //Add connection to SQL Server Db in appsettings.json
   var connection = Configuration.GetConnectionString("CoinToolDbContext");
   services.AddDbContext<CoinToolDbContext>(options => options.UseSqlServer(connection));
   services.AddMvc();
}

And here is my appsettings.json

{
  "Logging": {
    "IncludeScopes": false,
    "Debug": {
      "LogLevel": {
        "Default": "Warning"
      }
    },
    "Console": {
      "LogLevel": {
        "Default": "Warning"
      }
    },
    "ConnectionStrings": {
      "CoinToolDbContext": "Data Source=localhost;Initial Catalog=CoinToolDb;Integrated Security=True;Pooling=False"
    }
  }
}

And here is my project folder and file structure:

Answer 1

In your appsettings.json , the ConnectionStrings section is within the Logging section. So you cannot resolve the connection strings from the root IConfiguration object.

You should change your configuration so that ConnectionStrings is at the root:

{
  "Logging": {
    …
  },
  "ConnectionStrings": {
    "CoinToolDbContext": "…"
  }
}

Answer 2

Move the ConnectionStrings element outside the Logging section (The closing bracket was in the wrong place)

{
  "Logging": {
    "IncludeScopes": false,
    "Debug": {
      "LogLevel": {
        "Default": "Warning"
       }
      },
      "Console": {
        "LogLevel": {
          "Default": "Warning"
        }
      },
    },
    "ConnectionStrings": {
      "CoinToolDbContext": "Data Source=localhost;Initial Catalog=CoinToolDb;Integrated Security=True;Pooling=False"
    }      
}

And setup the context this way:

public void ConfigureServices(IServiceCollection services) 
{
    services.AddDbContext<CoinToolDbContext>(options.UseSqlServer(Configuration.GetConnectionString("CoinToolDbContext")));
}