.net core 设置读取JSON配置文件 appsettings.json

Startup.cs 中

    public class Startup

    {

        public Startup(IHostingEnvironment env)

        {

            Configuration = new ConfigurationBuilder()

                .SetBasePath(env.ContentRootPath)

                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)

                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)  //增加环境配置文件，新建项目默认有

                .AddEnvironmentVariables()

                .Build();

        }

        public IConfiguration Configuration { get; }

....

类库中

            var builder = new ConfigurationBuilder()

                .SetBasePath(Directory.GetCurrentDirectory())

                .AddJsonFile("appsettings.json")

                .AddJsonFile("appsettings.Test.json", true, reloadOnChange: true);

            var config = builder.Build();

            //读取配置

           var a = config["JWTSettings:Secret"];

使用.AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)这种方法可以保证可以修改正在运行的dotnet core 程序，不需要重启程序

使用Newtonsoft.Json 查询/修改，以及修改 appsettings.json 文件

ReadObject

        public IActionResult ReadObject()

        {

            string json = @"{

   'CPU': 'Intel',

   'PSU': '500W',

   'Drives': [

     'DVD read/writer'

     /*(broken)*/,

     '500 gigabyte hard drive',

     '200 gigabyte hard drive'

   ]

}";

            JsonTextReader reader = new JsonTextReader(new StringReader(json));

            var string1 = "";

            while (reader.Read())

            {

                if (reader.Value != null)

                {

                    string1 += "reader.Value != null: Token: " + reader.TokenType + ", Value: " + reader.Value + " <br/>";

                }

                else

                {

                    string1 += "reader.Value == null: Token: " + reader.TokenType + " <br/>";

                }

            }

            ViewData["string"] = string1;

            return View();

        }

ReadJSON 读取Json 文件

Newtonsoft.Json

使用Newtonsoft.Json效果如截图

    public class HomeController : Controller

    {

        private readonly IHostingEnvironment _hostingEnvironment;

        public HomeController(IHostingEnvironment hostingEnvironment)

        {

            _hostingEnvironment = hostingEnvironment;

        }

        public IActionResult ReadJSON()

        {

            string contentPath = _hostingEnvironment.ContentRootPath + @"\"; ;   //项目根目录

            var filePath = contentPath + "appsettings.json";

            using (StreamReader file = new StreamReader(filePath))

            using (JsonTextReader reader = new JsonTextReader(file))

            {

                JObject o2 = (JObject)JToken.ReadFrom(reader);

                string LicenceKey = (string)o2["appSettings"]["Key"];

                ViewData["string"] = LicenceKey;

                return View();

            }

        }

Microsoft.Extensions.Configuration

使用Microsoft.Extensions.Configuration

        public IActionResult Index()

        {

            var builder = new ConfigurationBuilder()

                .SetBasePath(Directory.GetCurrentDirectory())

                .AddJsonFile("appsettings.json")

                .AddJsonFile("appsettings.Test.json", true, reloadOnChange: true);

            var config = builder.Build();

            //读取配置

            ViewData["Secret"] = config["appSettings:Key"];

            return View();

        }

修改 appsettings.json后的效果

• Newtonsoft.Json
  
  

• Microsoft.Extensions.Configuration
  
  

修改 appsettings.json

StreamWriter直接覆盖

    public class HomeController : Controller

    {

        private readonly IHostingEnvironment _hostingEnvironment;

        public HomeController(IHostingEnvironment hostingEnvironment)

        {

            _hostingEnvironment = hostingEnvironment;

        }

        public IActionResult WriteJSON()

        {

            string contentPath = _hostingEnvironment.ContentRootPath + @"\"; ;   //项目根目录

            var filePath = contentPath + "appsettings.json";

            JObject jsonObject;

            using (StreamReader file = new StreamReader(filePath))

            using (JsonTextReader reader = new JsonTextReader(file))

            {

                jsonObject = (JObject)JToken.ReadFrom(reader);

                jsonObject["appSettings"]["Key"] = "asdasdasdasd";

            }

            using (var writer = new StreamWriter(filePath))

            using (JsonTextWriter jsonwriter = new JsonTextWriter(writer))

            {

                jsonObject.WriteTo(jsonwriter);

            }

            return View();

        }

效果如图

缺点 格式化的json和注释都没了