Asp .Net Core 如何读取appsettings.json配置文件？最近也有学习到如何读取配置文件的，主要是通过 IConfiguration，以及在Program中初始化完成的。那么今天给大家介绍下具体如何读取配置文件的。

	 

	首先创建一个读取配置文件的公共类GetAppsetting，我们可以看下此时配置文件中的内容

	

		

			
		
{
  "GetSetting": {
    "option1": "value1_from_json",
    "option2": -1,
    "subsection": {
      "suboption1": "subvalue1_from_json",
      "suboption2": 200
    }
  },
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*"
}
		

			
	


	 

	 

	在创建的GetAppsetting公共类中写如下代码

	

		     
		

			

				
			
   /// <summary>
        /// 实例化、调用GetAppsetting（）
        /// </summary>
        /// <param name="builder"></param>
        public static void connection(IConfiguration build)
        {
            getvalue = new GetAppsetting(build);
        }
 
        /// <summary>
        /// 在类中进行连接

        /// </summary>
        public static GetAppsetting getvalue { get; private set; }
 
        /// <summary>
        /// 最终实例化GetAppsetting（配置文件），读取到GetSetting下面的配置

        /// </summary>
        /// <param name="builder"></param>
        public GetAppsetting(IConfigurationbuild)
        {
            this.GetSettings = new GetSetting(build.GetSection("GetSetting"));
        }  
 
        public  GetSetting GetSettings { get; }
        /// <summary>
        /// 获取配置下面的具体属性的值

        /// </summary>
        public class GetSetting
        {
            public string option1 { get; }
            public GetSetting(IConfiguration Configuration)
            {
                this.option1 = Configuration.GetSection("option1").Value;
            }
        }
			

				
		
	


	 

	最后需要在Program中的Main函数中初始化

	

		

			
		
var Configuration = new ConfigurationBuilder()
             .Add(new JsonConfigurationSource { Path = "appsettings.json",  ReloadOnChange = true })
             .Build();
            GetAppsetting.connection(Configuration);


var a = GetAppsetting.getvalue.GetSettings.option1;//这样我们就可以拿到配置文件中GetSetting下面的option1的属性值了

		

			
	


	 

	 

	参考：https://docs.microsoft.com/zh-cn/aspnet/core/fundamentals/configuration/?view=aspnetcore-2.2

	           https://docs.microsoft.com/zh-cn/aspnet/core/fundamentals/configuration/options?view=aspnetcore-2.2