.netCore2.2升级3.1

1.  

 <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

2.

ConfigureServices 方法中 services.AddMvc() 改为 services.AddControllersWithViews()

3.

Configure 方法中 app.UseMvc() 改为 app.UseRouting() 与 app.UseEndpoints()

app.UseRouting();
    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllerRoute(
            name: "default",
            pattern: "{controller=Home}/{action=Index}/{id?}");
    });

4.更新  nuget包：

  Microsoft.EntityFrameworkCore.Design 3.1.7

  Microsoft.EntityFrameworkCore.Relational 3.1.7

  Microsoft.EntityFrameworkCore.SqlServer 3.1.7

  Microsoft.EntityFrameworkCore.Tools     3.1.7

  EFCore.BulkExtensions 3.1.5

 FluentValidation.AspNetCore==》 9.0.1

 Autofac.Extensions.DependencyInjection==》5.0.1

  Microsoft.AspNetCore.Mvc.NewtonsoftJson==》3.1.3

 Newtonsoft.Json==》12.0.3

 Swashbuckle.AspNetCore ==》5.5.1 

   Hangfire ==》1.7.12

   Hangfire.Console==》 1.4.2

5.  IFromFile 上传文件调整

6.  IWebHostBuilder 改为IHostBuilder

7，WEB项目中Program.cs文件，WebHost 改为 Host

public class Program
{
    public static void Main(string[] args)
    {
        CreateHostBuilder(args).Build().Run();
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            });
}