C ＃ - how to add and read appsetting in the console application JSON file

In this article , We'll learn how to do it in .NET Core Add and read from the console application appsettings.json file .
We turn on Visual Studio And create one called “ TestJson ” Console application for (.NET Core) project ：

Now? , We add a name called “Parameters.json” The file of , We will store one in it DB The connection string and the two named ValueABC and ValueDEF Parameters of ：

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "ConnectionStrings": {
    "DbConnection": "ExampleTestConnection"
  },
  "Parameter": {
    "ValueABC": "TestValue_ABC",
    "ValueDEF": "TestValue_DEF"
  }
}

Important note ： We must change the properties of the file “ Copy to output directory ” Set to ：“ If newer, copy ”：

Now? , In order to read Parameters.json file , We have to use NuGet Package add three libraries ：
Microsoft.Extensions.Configuration
Microsoft.Extensions.Configuration.FileExtensions
Microsoft.Extensions.Configuration.Json

Last , We modify Program.cs To read appsetting file ：

using Microsoft.Extensions.Configuration;
using System;
using System.IO;
 
namespace TestJson
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Starting reading file .json");
 
            Console.WriteLine($"ConnectioString: {GetDbConnection()}");
 
            Console.WriteLine($"The parameters are: {GetParameters()}");
 
            Console.ReadLine();
        }
 
        private static string GetDbConnection()
        {
            var builder = new ConfigurationBuilder()
                                .SetBasePath(Directory.GetCurrentDirectory())
                                .AddJsonFile("Parameters.json", optional: true, reloadOnChange: true);
 
            string strConnection = builder.Build().GetConnectionString("DbConnection");
 
            return strConnection;
        }
 
        private static string GetParameters()
        {
            var builder = new ConfigurationBuilder()
                                .SetBasePath(Directory.GetCurrentDirectory())
                                .AddJsonFile("Parameters.json", optional: true, reloadOnChange: true);
 
            var val1 = builder.Build().GetSection("Parameter").GetSection("ValueABC").Value;
            var val2 = builder.Build().GetSection("Parameter").GetSection("ValueDEF").Value;
 
            return $"The values of parameters are: {val1} and {val2}";
        }
    }
}

If we run the application , This will be the result ：