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.NET

跨平台开发平台 - 现代 C#、高性能、企业级开发框架

TL;DR

是什么：用于构建应用的免费、跨平台、开源开发平台。

为什么用：现代 C#、高性能、统一平台、优秀的工具链、企业级。

Quick Start

安装：从 dotnet.microsoft.com 下载

创建 Web API：

dotnet new webapi -n MyApi
cd MyApi
dotnet run

打开 https://localhost:5001/weatherforecast

创建最小 API：

dotnet new web -n MinimalApi
cd MinimalApi

编辑 Program.cs：

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "Hello World!");
app.MapGet("/users/{id}", (int id) => new { Id = id });

app.Run();

Cheatsheet

命令描述
dotnet new webapi创建 Web API 项目
dotnet new web创建最小 API
dotnet run运行应用
dotnet build构建项目
dotnet watch run热重载运行
dotnet add package Name添加 NuGet 包
dotnet ef migrations add添加 EF 迁移

Gotchas

最小 API

var builder = WebApplication.CreateBuilder(args);
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();
app.UseSwagger();
app.UseSwaggerUI();

app.MapGet("/api/users", () => new[] { "Alice", "Bob" });
app.MapPost("/api/users", (User user) => Results.Created($"/api/users/{user.Id}", user));
app.MapPut("/api/users/{id}", (int id, User user) => Results.Ok(user));
app.MapDelete("/api/users/{id}", (int id) => Results.NoContent());

app.Run();

record User(int Id, string Name);

基于控制器的 API

[ApiController]
[Route("api/[controller]")]
public class UsersController : ControllerBase
{
    [HttpGet]
    public ActionResult<IEnumerable<User>> GetAll() => Ok(users);

    [HttpGet("{id}")]
    public ActionResult<User> Get(int id) => Ok(user);

    [HttpPost]
    public ActionResult<User> Create(User user) => CreatedAtAction(nameof(Get), new { id = user.Id }, user);
}

依赖注入

// 注册服务
builder.Services.AddScoped<IUserService, UserService>();

// 在控制器中注入
public class UsersController : ControllerBase
{
    private readonly IUserService _service;

    public UsersController(IUserService service)
    {
        _service = service;
    }
}

Next Steps