如何将ASP.NET MVC Core 2.1项目升级至ASP.NET MVC Core 6？

一、csproj NuGet 包配置修改 #

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <NoWin32Manifest>true</NoWin32Manifest>
    <UserSecretsId>*******************</UserSecretsId>
    <ServerGarbageCollection>false</ServerGarbageCollection>
    <!-- Core 6.0 已默认启用 Razor 编译，无需单独配置 -->
  </PropertyGroup>

  <ItemGroup>
    <!-- 第三方包更新至兼容.NET 6的版本 -->
    <PackageReference Include="BCrypt-Core" Version="2.0.0" />
    <PackageReference Include="ClosedXML" Version="0.102.1" />
    <PackageReference Include="Magick.NET-Q16-AnyCPU" Version="13.6.0" />
    <!-- EF Core 升级至6.0版本 -->
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.25">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.25" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.25">
      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
      <PrivateAssets>all</PrivateAssets>
    </PackageReference>
    <!-- 代码生成工具升级 -->
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="6.0.16" />
    <PackageReference Include="System.Configuration.ConfigurationManager" Version="6.0.1" />
    <PackageReference Include="System.Linq.Dynamic.Core" Version="1.3.0" />
    <!-- Core 6.0 SDK已包含ASP.NET Core基础组件，无需单独引用 -->
  </ItemGroup>
</Project>

二、Program.cs 重构（合并Startup逻辑） #

var builder = WebApplication.CreateBuilder(args);

// 注册服务
var connection = builder.Configuration.GetConnectionString("DBconnection");
builder.Services.AddDbContext<HoshmandDBContext>(option => option.UseSqlServer(connection));

builder.Services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
    .AddCookie(options =>
    {
        options.LoginPath = "/Logins/UserLogin/";
        options.AccessDeniedPath = "/AccessDenied";
        options.ExpireTimeSpan = TimeSpan.FromHours(10);
    });

builder.Services.AddDistributedMemoryCache();
builder.Services.AddSession(options =>
{
    options.IdleTimeout = TimeSpan.FromHours(2);
    options.Cookie.HttpOnly = true;
    options.Cookie.IsEssential = true;
});

builder.Services.ConfigureApplicationCookie(option =>
{
    option.ExpireTimeSpan = TimeSpan.FromMinutes(540);
});

builder.Services.AddAuthorization(options =>
{
    options.AddPolicy("HasAccess", policy => policy.AddRequirements(new HasAccessRequirment()));
});

builder.Services.AddTransient<IAuthorizationHandler, HasAccessHandler>();
builder.Services.AddTransient<IMvcControllerDiscovery, MvcControllerDiscovery>();

// 添加MVC服务
builder.Services.AddControllersWithViews();

var app = builder.Build();

// 配置中间件
if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
}
else
{
    app.UseExceptionHandler("/Home/Error");
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseCookiePolicy();
app.UseSession();
app.UseAuthentication();
app.UseAuthorization();

// 配置路由
app.MapControllerRoute(
    name: "default",
    pattern: "{controller=UserProfiles}/{action=Index}/{id?}");

app.Run();

三、HomeController 修改 #

[DisplayName("Dashboard")]
[Authorize(policy: "HasAccess")]
public class HomeController : BaseController
{
    private readonly IMvcControllerDiscovery _mvcControllerDiscovery;
    // Core 3.0+ 已将IHostingEnvironment替换为IWebHostEnvironment
    private readonly IWebHostEnvironment _webHostEnvironment;

    public HomeController(HoshmandDBContext context, IWebHostEnvironment webHostEnvironment) : base(context)
    {
        _webHostEnvironment = webHostEnvironment;
    }

    public IActionResult Index(DateTime? date = null)
    {
        date = date ?? GetLocalDateTime();
        ViewBag.date = date;
        // 补全返回语句
        return View();
    }
}

四、LoginsController 优化 #

public class LoginsController : BaseController
{
    public LoginsController(HoshmandDBContext context) : base(context)
    {
    }

    [HttpGet]
    // 无异步操作时无需强行使用Task.Run，直接返回View即可
    public IActionResult UserLogin()
    {
        return View(new Login());
    }
}

内容的提问来源于stack exchange，提问作者Hedayat Hoshmand