8_在.Net Core库类项目中读取跨项目配置文件

如在asp.net Core的appsettings.json文件里加入下面的配置

    "ConnectionStrings": {
      "SchoolContext": "Server=.;Database=SchoolContext;uid=sa;password=123456"
    }

在Models类库里的ConfigurationHelper类里读取

namespace Models
{
    public static class ConfigurationHelper
    {
        private static IConfiguration _config;
        public static void Configure(IConfiguration config)
        {
            _config = config;
        }

        //根据配置文件键读取对应的值
        public static string GetConfigValueByKey()
        {
            //var value = _config["ConnectionStrings:SchoolContext"];//这样获取："ConnectionStrings:SchoolContext"

            var value = _config.GetSection("ConnectionStrings")["SchoolContext"];

            if (value == null)
            {
                return "";
            }
            return value;
        }
    }
}

在asp.netCore项目的Startup类的构造函数里进行注入

  public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
            ConfigurationHelper.Configure(Configuration);
        }

这样运行项目时调用类库的类里就能在类库里读取到配置文件信息。