如何在DBContext (实体框架核心)中从App.config (不是.net核心应用程序)中读取值

<configuration>
  <appSettings>
    <add key="ConnectionString" value="your_connection_string_here" />
  </appSettings>
</configuration>

using System.Configuration;

public class YourDBContext : DbContext
{
    public YourDBContext() : base(ConfigurationManager.AppSettings["ConnectionString"])
    {
        // 构造函数中使用ConfigurationManager.AppSettings["ConnectionString"]来获取配置值
    }
}