.Net Core中获取appsettings.json中的节点数据

获取ConnectionStrings节点数据

//appsettings.json

{
  "ConnectionStrings": {
    //DEV
    "DbConn": "Server=**;Integrated Security=no;User ID=**;PWD=**;initial catalog=DB**;MultipleActiveResultSets=true;Max Pool Size=1024;Min Pool Size=10;Pooling=true;"
    //QA
    //PROD
  },
  "ErrorPage": "/Error/Error",
  "Environment": "DEV"
}

//startup.cs

 public Startup(IConfiguration configuration)   //依赖注入
        {
            _configuration = configuration;
        }

        public IConfiguration _configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            string _conn;
            //config db
            try
            {
                //GetSection("Environment")获取Environment节点的数据
                if (_configuration.GetSection("Environment").Value.Equals("PROD", StringComparison.OrdinalIgnoreCase))
                {
                    var service = new DecryptService("ProjectICE_Portal");
                    _conn = service.Decrypt(_configuration.GetConnectionString("DbConn"));//加密获取节点数据
                }
                else
                {
                    _conn = _configuration.GetConnectionString("DbConn");//非加密
                }
            }
            catch (Exception ex)
            {
                throw new Exception($"Database connection initialization failed: {ex.Message}{ex.StackTrace}");
            }
}

第二种比较实用的方法

//Appsettings.json
{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning"
    }
  },
  "AllowedHosts": "*",
  "student": {
    "name": "小明",
    "age": 17,
    "classname": "5班"

  }
}

//新建一个实体类  实体类的属性和配置文件的配置项一致
  public class student
    {
        public string name { get; set; }
        public int age { get; set; }
       // public string classname { get; set; }
    }

//Startup.cs

            //services.AddOptions();   这两个必须在AddMvc上面
            services.Configure<student>(Configuration.GetSection("student"));
            services.AddMvc();

//Controller 依赖注入  using Microsoft.Extensions.Options;
public class OneController : Controller
    {
        private readonly IOptions<student> _log;
        public OneController(IOptions<student> logs)
        {
            _log = logs;
        }
        public IActionResult Index()
        {
            var a = _log.Value;
            ViewBag.a = a.name;   //"小明"
            return View();
        }
    }