appsettings.json，给类库项目引入 Microsoft.Extensions.Configuration 和 Microsoft.Extensions.Configuration.Json程序包，类库中加载appsettings.json配置文件代码如下：
{ ?"ConnectionStrings": { ???"conn": "Server=192.168.10.254;port=3308;database=riyunping_qdezge20180225;uid=root;pwd=123456;" ?}, ?"AppSettings": { ???"AccessKey": "111111", ???"SecretKey": "22222", ???"Bucket": "3333333", ???"Domain": "http://wwww.domain.com" ?}, ?"Logging": { ???"IncludeScopes": false, ???"LogLevel": { ?????"Default": "Warning" ???} ?}, ?"wmUrl": "https://www.baidu.com"}
using Microsoft.Extensions.Configuration;using Microsoft.Extensions.Configuration.Json;using System;using System.Collections.Generic;using System.Text;namespace Infrastructure{ ???/// <summary> ???/// 读取配置文件 ???/// </summary> ???public class AppConfigurtaionServices ???{ ???????public static IConfiguration Configuration { get; set; } ???????static AppConfigurtaionServices() ???????{ ???????????//ReloadOnChange = true 当appsettings.json被修改时重新加载 ???????????????????????Configuration = new ConfigurationBuilder() ???????????.Add(new JsonConfigurationSource { Path = "appsettings.json", ReloadOnChange = true }) ???????????.Build(); ???????} ???}}
使用方法如下，读取数据库链接字符串
AppConfigurtaionServices.Configuration.GetConnectionString("conn"); //得Server=Server=192.168.10.254;port=3308;database=abc;uid=root;pwd=123456;读取一级配置节点配置
AppConfigurtaionServices.Configuration["wmUrl"];//得 https://www.baidu.com
读取二级子节点配置
AppConfigurtaionServices.Configuration["Appsettings:AccessKey"];//得到 111111AppConfigurtaionServices.Configuration["Appsettings:SecretKey"];//得到 22222
注意，如果AppConfigurtaionServices类中抛出FileNotFoundException异常，说明目录下未找到appsettings.json文件，这时请在项目appsettings.json文件上右键——属性——将“复制到输出目录”项的值改为“始终复制”即可。
.net core mvc 类库读取配置文件
原文地址：https://www.cnblogs.com/liangwenchao-912/p/8671965.html