How can I read the appsettings.json in a .Net 6 console application?-CodePudding

I try to create a .Net 6 Console Application but having troubles reading my appsettings.json file. In a web application I could use this...

var builder = WebApplication.CreateBuilder(args);

But what would I use in a console application? I get this error when trying to add it to program.cs. "The name 'WebApplication' does not exist in the current context"

CodePudding user response：

Add these two nuget packages in your application

Microsoft.Extensions.Configuration

Microsoft.Extensions.Configuration.Json

Then you can use ConfigurationBuilder to use appsettings.json file

var configuration =  new ConfigurationBuilder()
     .SetBasePath(Directory.GetCurrentDirectory())
     .AddJsonFile($"appsettings.json");
            
var config = configuration.Build();
var connectionString = config["ConnectionString"];

Getting Values from AppSettings in Console Application

Adding AppSettings in .net core app

CodePudding user response：

You could use DI to get IConfiguration interface and with it you can access the appsettings.

CodePudding user response：

In a console app I add the appsettings.json and user secrets like this, you may also have a development json file as well.

internal class Program
{
    internal static IConfigurationRoot Configuration;

    public static void Main()
        => new Program().MainAsync().GetAwaiter().GetResult();

    private async Task MainAsync()
    {
        var configurationBuilder = new ConfigurationBuilder();
        configurationBuilder.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true);
        configurationBuilder.AddUserSecrets(typeof(Program).GetTypeInfo().Assembly, optional: false);
        Configuration = configurationBuilder.Build();

        ...
    }
}

Then elsewhere in the console app in any class you can simply call it like this

var someSetting = Program.Configuration["SomeSetting"];

If you want a strongly typed class then see this answer .net core Console application strongly typed Configuration on SO

CodePudding user response：

Link to docs: https://docs.microsoft.com/en-us/dotnet/core/extensions/configuration

Nuget packages needed to doing it:

<PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="6.0.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="6.0.0" />
    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="6.0.0" />

using Microsoft.Extensions.Configuration;

    // Build a config object, using env vars and JSON providers.
    IConfiguration config = new ConfigurationBuilder()
        .AddJsonFile("appsettings.json")
        .AddEnvironmentVariables()
        .Build();
    
    // Get values from the config given their key and their target type.
    Settings settings = config.GetRequiredSection("Settings").Get<Settings>();
    
    // Write the values to the console.
    Console.WriteLine($"KeyOne = {settings.KeyOne}");
    Console.WriteLine($"KeyTwo = {settings.KeyTwo}");
    Console.WriteLine($"KeyThree:Message = {settings.KeyThree.Message}");

// Application code which might rely on the config could start here.
// This will output the following:
//   KeyOne = 1
//   KeyTwo = True
//   KeyThree:Message = Oh, that's nice...

JSON File (appsettings.json)

{
    "Settings": {
        "KeyOne": 1,
        "KeyTwo": true,
        "KeyThree": {
            "Message": "Oh, that's nice..."
        }
    }
}

UPD: i checked approach, and its works; My code:

// See https://aka.ms/new-console-template for more information

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;

Console.WriteLine("Hello, World!");
ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();
IConfiguration c = configurationBuilder.AddJsonFile("appsettings.json").AddEnvironmentVariables().Build();
var k = c.GetRequiredSection("Settings").Get<Settings>().KeyOne;
var n = 1;

public class NestedSettings
{
    public string Message { get; set; } = null!;
}
public class Settings
{
    public int KeyOne { get; set; }
    public bool KeyTwo { get; set; }
    public NestedSettings KeyThree { get; set; } = null!;
}