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。