robbinhsu / route

實作Route常用做法

Route

---

Attribute Routing

加入 [Route] 到 Controller：

[Route("books")]
[ApiController]
public class BooksController : ControllerBase
{
    // GET: /Books
    [HttpGet]
    [Route("")]
    public async Task<ActionResult<IEnumerable<Book>>> GetBook() { ... }
    
    // GET: /Books/5
    [HttpGet()]
    [Route("{id:int}")]
    public async Task<ActionResult<Book>> GetBook(int id) { ... }
    
    // 使用Router才能支援 RESTful API 中常見的某些 URI 模式
    // 查詢特定 Author
    // GET: authors/{authorId}/books
    [HttpGet]
    [Route("~/authors/{authorId:int}/books")]
    public IActionResult GetBooksByAuthor(int authorId) { ... }
    
    // GET: /books/date/2016-06-27
    [HttpGet]
    //[Route("date/{publishDate:datetime}")]
    //[Route("date/{publishDate:datetime:regex(\d{{4}}-\d{{2}}-\d{{2}})}")]
    [Route(@"date/{publishDate:datetime:regex(\d{{4}}-\d{{2}}-\d{{2}})}")]
    public IActionResult Get(DateTime publishdate) { ... }
}

使用 [RoutePrefix] 屬性為整個控制器設定公共前置前置字串:

[RoutePrefix("api/books")]
public class BooksController : ApiController
{
    // GET api/books
    [Route("")]
    public IEnumerable<Book> Get() { ... }

    // GET api/books/5
    [Route("{id:int}")]
    public Book Get(int id) { ... }

    // POST api/books
    [Route("")]
    public HttpResponseMessage Post(Book book) { ... }
}

---

Map動詞()

• 判斷請求來源的資訊(例如瀏覽器)

  app.Use((context, next) =>
  {
      var userAgent = context.Request.Headers["User-Agent"].ToString();
      //只允許Postman通過
      if (userAgent.Contains("Postman"))
      {
       return next();
      }
      else
      {
       return context.Response.WriteAsync("Error");
      }
  });

• 建立 Middleware 類別
  • 把自製的 Middleware 邏輯獨立出來。 自製的Middleware中要有一個非同步的 Invoke 方法。

  public class SampleMiddleware
  {
      private readonly RequestDelegate _next;
  
      public SampleMiddleware(RequestDelegate next)
      {
          _next = next;
      }
  
      public async Task Invoke(HttpContext context)
      {
          var userAgent = context.Request.Headers["User-Agent"].ToString();
          if (userAgent.Contains("Postman"))
          {
              await _next(context);
          }
          else
          {
              await context.Response.WriteAsync("Error");
          }
      }
  }

• 註冊到Startup的Configure

  app.UseMiddleware<BrowserMiddleware>();

---

參考資料：
精準解析 ASP.NET Core Web API
ASP.NET Web API 中的路由
ASP.NET Web API 中的路由和動作選取
ASP.NET Web API 2 中的屬性路由 [鐵人賽 Day03] ASP.NET Core 2 系列 - Middleware

---

• 如果使用空白專案，要在Startup.cs新增

  • Configuration

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

  • ServiceCollection

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers();
    }

  • endpoints.MapControllers();

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });
    }

• 新增 Web API Controller
  於 Add Scaffold → 選擇：Web API 2 Controller with actions, using Entity Framework

  • Model class: Book
  • Controller name: BooksController
  • Data context class: 選擇 + 號：BookSampleContext

• 加入SeedDate

  • 開啟 Package Manager Console，輸入以下指令：

    PM> Add-Migration initial

  • 在 DbContext 衍生類別覆寫 OnModelCreating()，加入SeedData。
  • 輸入以下指令，Migrations資料夾就會產生SeedData

    PM> Add-Migration seeddata  
    PM> Update-Database