Bdtjtk

You need to add the package below:

    "Microsoft.Extensions.Configuration.Json": "1.0.0"

Another way:

appsettings.json:

{

    "greeting": "A configurable hello, to you!"

}

Startup.cs:

using Microsoft.Extensions.Configuration; // for using IConfiguration

using System.IO; // for using Directory



public class Startup

{

    public IConfiguration Configuration { get; set; }



    public Startup()

    {

        var builder = new ConfigurationBuilder();

        builder.SetBasePath(Directory.GetCurrentDirectory());

        builder.AddJsonFile("appsettings.json");



        Configuration = builder.Build();

    }    

}

In the Configure method:

app.Run(async (context) =>

{

    // Don't use:

    // string greeting = Configuration["greeting"]; // null



    string greeting = Configuration.GetSection("greeting").Value;

    await context.Response.WriteAsync(greeting)

});

An alternative solution I found from this blog post works as well. It has the added benefit of not needing to modify the Startup.cs file's Startup method signature.

In the buildOptions section add copyToOutput with the name of the file.

{

  "version": "1.0.0-*",

  "buildOptions": {

    "emitEntryPoint": true,

    "copyToOutput": "appsettings.json"

  },

  .... The rest of the file goes here ....

Actually for this you need to provide provide root path from your environment variable so you need to pass IHostingEnvironment reference to provide root path:

public Startup(IHostingEnvironment env)

{

    var builder = new ConfigurationBuilder()

                          .SetBasePath(env.ContentRootPath)

                          .AddJsonFile("appsettings.json");

    Configuration = builder.Build();

}

and if you can't find AddJsonFile method then you have to add using Microsoft.Extensions.Configuration.Json;

In .NET Core 2.0, you would update the .csproj file to copy the JSON file to the output directory so that it can be accessed, like so:

<ItemGroup>

    <Folder Include="wwwroot" />

    <None Include="appsettings.json" CopyToOutputDirectory="Always" />

</ItemGroup>

Right click appsettings.json -> Properties, then makes sure that Copy to Output Directory is set to "Copy Always"

The answers that suggest adding .SetBasePath(env.ContentRootPath) in Startup.cs depend upon a prior step.

First, add the line .UseContentRoot(Directory.GetCurrentDirectory()) to your WebHostBuilder construction in Program.cs like so:

public class Program

{

    public static void Main(string args)

    {

        var config = new ConfigurationBuilder()

            .SetBasePath(Directory.GetCurrentDirectory())

            .AddEnvironmentVariables()

            .Build();



        var host = new WebHostBuilder()

            .UseConfiguration(config)

            .UseKestrel()

            .UseContentRoot(Directory.GetCurrentDirectory())

            .UseStartup<Startup>()

            .Build();



        host.Run();

    }

}

Then the following will work:

public Startup(IHostingEnvironment env)

{

    var builder = new ConfigurationBuilder()

        .SetBasePath(env.ContentRootPath)

        .AddJsonFile("appsettings.json");



    Configuration = builder.Build();

}

If you have done anything with Project Debug Properties, then you may have inadvertently overwritten the starting directory:

Project -> Right-click -> Properties -> Debug -> Profile and then look at the entry in Working Directory.

The simplest is that it be blank.

You Need to istall Configuration.Json package from Microsoft.Extensions
or just add Microsoft.Extensions.Configuration.Json to y