How to C#: add a settings file to your Console application

What if I want to create a quick console application and keep all my settings in a seperate appsettings.json file? The default C# application template doesn't provide this for us, so I think it might be useful to write a little guide to make this easier in the future.

Required

• .Net 5.0 console application
• The following packages:

<ItemGroup>
    <PackageReference Include="Microsoft.Extensions.Configuration" Version="5.0.1" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="5.0.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="5.0.0" />
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="5.0.0" />
</ItemGroup>

Guide

Simply follow these steps to load your appsettings into a class for easy use.

• Add the references above to the project
• Add a new class called ApiSettings.cs

    public class ApiSettings
    {
        public string TwitterApiKey { get; set; }
        public string TwitterApiSecret { get; set; }
        public string BearerToken { get; set; }
    }

• Add a new class called Startup.cs

public class Startup
    {
        public Startup()
        {
            var builder = new ConfigurationBuilder()
                      .SetBasePath(Directory.GetCurrentDirectory())
                      .AddJsonFile("appsettings.json", optional: false);

            IConfiguration config = builder.Build();

            ApiSettings = config.GetSection("ApiSettings").Get<ApiSettings>();

        }

        public ApiSettings ApiSettings { get; private set; }
    }

• Add your appsettings.json with content similar to something like this:

  {
"ApiSettings": {
    "TwitterApiKey": "",
    "TwitterApiSecret": "",
    "BearerToken": ""
  }
}

• Right click on the file appsettings.json and set the copy output to Copy always

• Make sure the fields in the section 'ApiSettings' match your ApiSettings.cs class.

• Go back to your Program.cs file and add the following line:
  var startup = new Startup();

• We can now use the values in the ApiSettings section of our appsettings. You can try it out with the following code.

All Done!

Now you can experiment and make it even more advanced yourself!

For a more advanced tutorial implementing this into an API look here https://dev.to/iamrule/how-to-c-add-configuration-to-your-net-8-web-api-application-4cjf

Comments

[Vaclav Elias]

Your required section should be saying .NET 6 instead of .NET 5 as you are referencing .NET 6 NuGet packages.

[Roel]

Hey, thanks for your comment! The v6.0 packages actually work on a .net5 application in my example. I will update the article to reference the v5 packages to make it easier to understand for new readers.

[Vaclav Elias]

You are welcome. I know that it works, I only mentioned it so we don't confuse new learners 🤣