webBuilder.ConfigureAppConfiguration((hostingContext, config) =>
                    {
                        IHostEnvironment env = hostingContext.HostingEnvironment;

　　　　　　　　　　　　　　//调用Clear 会报错，因时间就没有深查了
                        config.Sources.ForEach(source =>
                        {
                            if (source is JsonConfigurationSource)
                            {
                                var jsonConfigurationSource = (JsonConfigurationSource)source;
                                jsonConfigurationSource.ReloadOnChange = false;
                            }
                        });

                        config.AddJsonFile("appsettings.json", optional: true, reloadOnChange: false)
                              .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: false);

                        if (env.IsDevelopment() && !string.IsNullOrEmpty(env.ApplicationName))
                        {
                            var appAssembly = Assembly.Load(new AssemblyName(env.ApplicationName));
                            if (appAssembly != null)
                            {
                                config.AddUserSecrets(appAssembly, optional: true);
                            }
                        }

                        config.AddEnvironmentVariables();

                        if (args != null)
                        {
                            config.AddCommandLine(args);
                        }
                    }).UseStartup<Startup>();