.Net Core Web应用加载读取Json配置文件

⒈添加Json配置文件并将“复制到输出目录”属性设置为“始终复制”

 {
   "Logging": {
     "LogLevel": {
       "Default": "Warning"
     }
   },
   "AllowedHosts": "*"
 }

 {
   "ConnectionStrings": {
     "StudyConnStr": "Data Source=.;Initial Catalog=Study;User ID=sa;Password=admin"
   }
 }

⒉在Program中加载配置文件

 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging;
 
 namespace EF_SqlServer
 {
     public class Program
     {
         public static void Main(string[] args)
         {
             CreateWebHostBuilder(args).Build().Run();
 
         }
 
         public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
             WebHost.CreateDefaultBuilder(args)
             .ConfigureAppConfiguration((hostingContext, config) =>
             {
                 config.SetBasePath(Directory.GetCurrentDirectory());
                 config.AddJsonFile("//Config//dbconfig.json", true, true);
                 config.AddJsonFile("appsettings.json", true, true);
             }).UseStartup<Startup>();
     }
 }

⒊使用配置文件中的相关属性

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.HttpsPolicy;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 
 namespace EF_SqlServer
 {
     public class Startup
     {
         public Startup(IConfiguration configuration)
         {
             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)
         {
             services.Configure<CookiePolicyOptions>(options =>
             {
                 // This lambda determines whether user consent for non-essential cookies is needed for a given request.
                 options.CheckConsentNeeded = context => true;
                 options.MinimumSameSitePolicy = SameSiteMode.None;
             });
             string dbConn = Configuration.GetSection("ConnectionStrings").GetSection("StudyConnStr").Value;
             string logDef = Configuration["Logging:LogLevel:Default"];
             services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
         public void Configure(IApplicationBuilder app, IHostingEnvironment env)
         {
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
             }
             else
             {
                 app.UseExceptionHandler("/Home/Error");
                 // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                 app.UseHsts();
             }
 
             app.UseHttpsRedirection();
             app.UseStaticFiles();
             app.UseCookiePolicy();
 
             app.UseMvc(routes =>
             {
                 routes.MapRoute(
                     name: "default",
                     template: "{controller=Home}/{action=Index}/{id?}");
             });
         }
     }
 }