ASP.NET Core轻松入门Bind读取配置文件到C#实例

首先新建一个ASP.NET Core空项目,命名为BindReader

然后 向项目中添加一个名为appsettings.json的json文件，为什么叫appsettings呢？  打开Program.cs 

 public class Program
    {
        public static void Main(string[] args)
        {
            BuildWebHost(args).Run();
        }

        public static IWebHost BuildWebHost(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>()
                .Build();
    }

代码中的IWebHost在启动时，具有自动加载appsettings.json的特性，所以命名成这个就不用特意地加载了。

然后再appsetting.json中写入数据，数据如下：

{
  "Name": "pragram language",
  "Items": [
    {
      "Language": "C#",
      "Tool": "visual studio"
    },
    {
      "Language": "JAVA",
      "Tool": "Elcipse"
    }
  ]

}

在项目中添加一个Class的类，根据该json文件的结构，创建Clsaa类中的内容，注意Class中的字段名称和Json中的字段名称必须要个匹配，一一对应。

Claa类中的代码如下：

 public class Class
    {
        public String Name { get; set; }
        public List<Item> Items { get; set; }
    }
    public class Item
    {
        public string Language { get; set; }
        public string Tool { get; set; }
    }

可以看到字段与Json内的数据时一一对应的。

打开startup.cs文件

修改startup.cs的构造函数并添加Connection属性

 public IConfiguration Configuration { get; set; }

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

实例化一个Class类

   var myClass = new Class();

通过connection将配置文件中的数据来绑定Class实例

 Configuration.Bind(myClass);

数据展现

 Console.WriteLine($"name:{myClass.Name}");
                Console.WriteLine();
                for (int i = 0; i < myClass.Items.Count; i++)
                {
                    await context.Response.WriteAsync($"language:{myClass.Items[i].Language}");
                    await context.Response.WriteAsync($"tool:{myClass.Items[i].Tool}");
                }

总体的startup.cs中的代码如下：

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.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;

namespace BindReader
{
    public class Startup
    {
        public IConfiguration Configuration { get; set; }

        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
        }

        // 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();
            }

            app.Run(async (context) =>
            {
                //var con = new ConfigurationBuilder().AddJsonFile("appsettings.json");
                //Configuration = con.Build();
                var myClass = new Class();
               
                Configuration.Bind(myClass);
                Console.WriteLine($"name:{myClass.Name}");
                Console.WriteLine();
                for (int i = 0; i < myClass.Items.Count; i++)
                {
                    await context.Response.WriteAsync($"language:{myClass.Items[i].Language}");
                    await context.Response.WriteAsync($"tool:{myClass.Items[i].Tool}");
                }
                await context.Response.WriteAsync("Hello World!");
            });
        }
    }
}

以上完整github项目代码地址：https://github.com/liuzhenyulive/BindReader

有任何疑问可以在评论区留言。