要解决"AspNetCore - Serilog - 错误地记录到IISExpress文件夹"问题，您可以按照以下步骤进行操作：

1. 在项目中安装必要的NuGet包：

   dotnet add package Serilog.AspNetCore
   dotnet add package Serilog.Settings.Configuration
   

2. 在Program.cs文件中配置Serilog：

   using Microsoft.AspNetCore.Hosting;
   using Microsoft.Extensions.Hosting;
   using Serilog;
   
   public class Program
   {
       public static void Main(string[] args)
       {
           CreateHostBuilder(args).Build().Run();
       }
   
       public static IHostBuilder CreateHostBuilder(string[] args) =>
           Host.CreateDefaultBuilder(args)
               .UseSerilog((hostingContext, loggerConfiguration) =>
               {
                   loggerConfiguration
                       .ReadFrom.Configuration(hostingContext.Configuration)
                       .Enrich.FromLogContext()
                       .WriteTo.File("logs/log.txt", rollingInterval: RollingInterval.Day);
               })
               .ConfigureWebHostDefaults(webBuilder =>
               {
                   webBuilder.UseStartup();
               });
   }
   

3. 在appsettings.json中添加配置：

   {
     "Serilog": {
       "Using": [ "Serilog.Sinks.File" ],
       "MinimumLevel": "Information",
       "WriteTo": [
         {
           "Name": "File",
           "Args": {
             "path": "logs/log.txt",
             "rollingInterval": "Day"
           }
         }
       ]
     }
   }
   

4. 在Startup.cs中启用Serilog：

   using Microsoft.AspNetCore.Builder;
   using Microsoft.AspNetCore.Hosting;
   using Microsoft.Extensions.Configuration;
   using Microsoft.Extensions.DependencyInjection;
   using Microsoft.Extensions.Hosting;
   
   public class Startup
   {
       public Startup(IConfiguration configuration)
       {
           Configuration = configuration;
       }
   
       public IConfiguration Configuration { get; }
   
       public void ConfigureServices(IServiceCollection services)
       {
           // 配置其他服务
   
           services.AddControllers();
       }
   
       public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
       {
           // 配置其他中间件
   
           if (env.IsDevelopment())
           {
               app.UseDeveloperExceptionPage();
           }
           else
           {
               app.UseExceptionHandler("/Home/Error");
           }
   
           app.UseSerilogRequestLogging(); // 启用Serilog请求日志记录
   
           app.UseRouting();
   
           app.UseAuthorization();
   
           app.UseEndpoints(endpoints =>
           {
               endpoints.MapControllers();
           });
       }
   }
   

5. 运行应用程序，并确保logs文件夹位于项目根目录下，并且具有写入权限。

现在，您的应用程序的日志将被记录到logs/log.txt文件中。