前言：在与传统的asp.net MVC项目相比,.net core项目在项目目录的文件结构上和功能上与前者都有很大的区别。例如：在.net core中使用Startup.cs取代Global.asax文件用于加载应用程序的配置和各种启动项。appsettings.json取代web.config文件用于存储应用程序所需的配置参数等等。。。

OK！步入正题,下面来说一下如何读取Json配置文件中的参数。

第一种:使用IConfiguration接口

我们先在appsettings.json中配置好数据库连接字符串,然后读取它

{"Connection": {"dbContent": "Data Source=.;Initial Catalog=test;User ID=sa;Password=123456"},"Logging": {"LogLevel": {"Default": "Information","Microsoft": "Warning","Microsoft.Hosting.Lifetime": "Information"}

},"AllowedHosts": "*"}

在控制器中注入IConfiguration接口

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Threading.Tasks;usingMicrosoft.AspNetCore.Mvc;usingMicrosoft.Extensions.Configuration;namespaceRead.json.Controllers

{

[ApiController]

[Route("[controller]")]public classReadController : Controller

{privateIConfiguration _configuration;publicReadController(IConfiguration configuration)

{

_configuration=configuration;

}

[HttpPost]public async TaskReadJson()

{

//读参string conn = _configuration["Connection:dbContent"];return "";

}

}

}

当然也可以读取数组形式的json,一样的先在appsettings.json中写好配置参数，如下：

{"Connection": {"dbContent": "Data Source=.;Initial Catalog=test;User ID=sa;Password=123456"},//------------------------

"Content": [

{"Trade_name": {"test1": "小熊饼干","test2": "旺仔QQ糖","test3": "娃哈哈牛奶"}

}

],//------------------------

"Logging": {"LogLevel": {"Default": "Information","Microsoft": "Warning","Microsoft.Hosting.Lifetime": "Information"}

},"AllowedHosts": "*"}

比如我们想读取test1

string commodity_test1 = _configuration["Content:0:Trade_name:test1"];

第二种：使用IOptions来读取json配置文件

先把NuGet包导进项目：Microsoft.Extensions.Options.ConfigurationExtensions

首先在appsettings.json中添加节点如下

{"Connection": {"dbContent": "Data Source=.;Initial Catalog=test;User ID=sa;Password=123456"},//------------------------

"Content": [

{"Trade_name": {"test1": "小熊饼干","test2": "旺仔QQ糖","test3": "娃哈哈牛奶"}

}

],//------------------------

"Logging": {"LogLevel": {"Default": "Information","Microsoft": "Warning","Microsoft.Hosting.Lifetime": "Information"}

},"AllowedHosts": "*",//==============================

"Information": {"school": {"Introduce": {"Name": "实验小学","Class": "中班","Number": "15人"},"Region": {"Province": "湖北","City": "武汉","Area": "洪山区"},"Detailed_address": [

{"Address": "佳园路207号"}

]

}

}//==============================

}

然和再建立一个与这个节点"相同"的类

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Threading.Tasks;namespaceRead.json

{public classInformation

{public School school { get; set; }

}public classSchool

{public Introduce Introduce { get; set; }public Region Region { get; set; }public List data { get; set; }

}public classIntroduce

{public string Name { get; set; }public string Class { get; set; }public string Number { get; set; }

}public classRegion

{public string Province { get; set; }public string City { get; set; }public string Area { get; set; }

}public classDetailed_address

{public string Address { get; set; }

}

}

在Startup中添加如下代码

#region 服务注册,在控制器中通过注入的形式使用services.AddOptions();

services.Configure(Configuration.GetSection("Information"));#endregion

控制器中使用：

usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Threading.Tasks;usingMicrosoft.AspNetCore.Mvc;usingMicrosoft.Extensions.Configuration;usingMicrosoft.Extensions.Options;namespaceRead.json.Controllers

{

[Route("api/[controller]/[action]")]

[ApiController]public classReadController : Controller

{privateIConfiguration _configuration;readonlyInformation _Information;readonly IOptions_options;publicReadController(IConfiguration configuration,

Information Information,

IOptionsoptions)

{

_configuration=configuration;

_Information=Information;

_options=options;

}

[HttpGet]public async TaskReadInformation()

{string Address = _options.Value.school.Region.Province + "-" +_options.Value.school.Region.City+ "-" +_options.Value.school.Region.Area+ "-" +_options.Value.school.Detailed_address[0].Address + "-" +_options.Value.school.Introduce.Name+ "-" +_options.Value.school.Introduce.Class+ "-" +_options.Value.school.Introduce.Number;returnJson(Address);

}

[HttpPost]public async TaskReadJson()

{string conn = _configuration["Connection:dbContent"];string commodity = _configuration["Content:0:Trade_name:test1"];return "";

}

}

}

第三种：这种应该比较常见,任意读取自定义的json文件

首先建立一个json文件

{"system_version": {"Edition": ".Net Core 3.0","Project_Name": "Read.json"}

}

再建一个类,封装一个方法

usingMicrosoft.Extensions.Configuration;usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Threading.Tasks;namespaceRead.json

{public classJson_File

{publicIConfigurationRoot Read_Json_File()

{//这句代码会读取read_json.json中的内容

return new ConfigurationBuilder().AddJsonFile("read_json.json")

.Build();

}

}

}

在控制器中调用：

[HttpGet]public async TaskReadSystemVersion()

{var configuration =_json_File.Read_Json_File();string system = "使用的是" + configuration["system_version:Edition"] + "的版本" + "," +

"项目名称是" + configuration["system_version:Project_Name"];return Json(new{

data=system

});

}

Demo地址：Func

func = (address) => git cloneaddress;var project = func("https://github.com/Davenever/Read_Json.git");