为什么 DNX 运行代码两次

我想将我的框架移植到新的 .net 核心，所以我创建了一个空应用程序，添加了一个静态成员来感受行为，每个请求增加一个 int，但它运行两次，一次用于请求，一次在请求之后，所以而不是得到 1，2，3，4...我得到 1，3，5，7...

public class Startup
{
    // This method gets called by the runtime. Use this method to add services to the container.
    // For more information on how to configure your application, visit http://go.microsoft.com/fwlink/?LinkID=398940
    public void ConfigureServices(IServiceCollection services)
    {      
    }
    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app)
    {
        app.UseIISPlatformHandler();
        app.Run(async (context) =>
        {
            state++;
            await  context.Response.WriteAsync(state.ToString()); 
        }); 
    }
    public static int state;
    // Entry point for the application.
    public static void Main(string[] args) => Microsoft.AspNet.Hosting.WebApplication.Run<Startup>(args);
}