asp.net core 读取连接字符串

从类库中读取配置文件需要添加程序集：

　　Install-Package Microsoft.Extensions.Configuration

开源项目 net core？　　Install-Package Microsoft.Extensions.Configuration.Json

{"ConnectionStrings": {"Default": "Data Source = DESKTOP-A8O71KP\\MSSQLSERVER2017;Initial Catalog = test; User ID = sa;Password =123"},"Logging": {"LogLevel": {"Default": "Warning"}},"AllowedHosts": "*"
}

 

using System;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Configuration.Json;
using System.IO;

namespace Common
{public class ConfigurationManager{public readonly static IConfiguration Configuration;static ConfigurationManager(){
　　　　　　　//Configuration = new ConfigurationBuilder().SetBasePath(Directory.GetCurrentDirectory()).AddJsonFile("appsettings.json", optional: true).Build();}public static string conn {get {return Configuration.GetConnectionString("Default"); }}}
}

asp空字符串转null，参考：https://docs.microsoft.com/zh-cn/aspnet/core/fundamentals/configuration/options?view=aspnetcore-2.2