.NET 6 中缺少 Startup.cs 类

Question

我在 .NET 5 中创建了 REST API，一切都运行良好，但最近我转移到 .NET 6 并意识到不存在startup.cs 类。由于没有startup.cs，如何在.NET 6 中添加数据库上下文？

Answer 1

在 .NET 6 中，Microsoft 删除了 Startup.cs 类。只需转到program.cs 文件，您可以在其中添加连接字符串，然后您必须使用builder.Services.AddDbContext

老办法是

services.AddDbContext

只需使用builder.Services，然后您就可以实现您想要的。

Answer 2

在 .NET 6 中，它们统一Startup.cs为Program.cs一个 Program.cs。

现在注册中间件、服务并将 DbContext 和其他所有内容添加到 Program.cs 文件中。

以下是 Program.cs 文件的示例：

using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);
//Register services here
builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer(       
builder.Configuration.GetConnectionString("DefaultConnection")       
));
builder.Services.AddScoped<IUnitOfWork, UnitOfWork>();
//builder.Services.AddAuthentication(...)
var app = builder.Build();
//app.UseAuthentication();

欲了解更多信息，请访问此线程。

Answer 3

创建一个名为“Startup.cs”的新类。将此模板粘贴到其中；

public class Startup
{
    public IConfiguration Configuration { get; }
    public Startup(IConfiguration configuration)
    {
        this.Configuration = configuration;
    }

    // This method gets called by the runtime. Use this method to add serices to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        //services.AddDbContext...
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(WebApplication app, IWebHostEnvironment env)
    {

    }
}

现在，您可以将 Program.cs 类修改为如下所示；

var builder = WebApplication.CreateBuilder(args);
var startup = new Startup(builder.Configuration); // My custom startup class.

startup.ConfigureServices(builder.Services); // Add services to the container.

var app = builder.Build();

startup.Configure(app, app.Environment); // Configure the HTTP request pipeline.

app.Run();

现在，事情以旧的方式组织得更好。使用 ASP.NET Core 5 的人会有宾至如归的感觉。您在ConfigureServices() 和Configure() 中放入的内容将取决于您的项目和需求。例如，以下是作为起点的示例 ASP.NET Core 7 MVC 项目的 Startup.cs 的样子；

public class Startup
{
    public IConfiguration Configuration { get; }
    public Startup(IConfiguration configuration)
    {
        this.Configuration = configuration;
    }

    // This method gets called by the runtime. Use this method to add serices to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllersWithViews();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(WebApplication app, IWebHostEnvironment env)
    {
        if (!env.IsDevelopment())
        {
            app.UseExceptionHandler("/Home/Error");
            // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthorization();

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

Answer 4

对于那些尝试添加瞬态、单例或范围服务的人来说要清楚......

以前在Startup.cs中，添加服务如下所示：

public void ConfigureServices(IServiceCollection services)
{
    services.AddTransient<IEmailService, EmailService>();
}

现在在Program.cs中，它看起来像这样：

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddTransient<IEmailService, EmailService>();