HttpContext

HttpContext 類封裝了HTTP Request 和 HTTP Response。
當(dāng)收到一條HTTP Request 請求時，就會實例化一個HttpContext對象。HttpContext對象可以被中間件訪問。
注意：HttpContext 不是線程安全的。

讀取 HttpContext 的值

從Razer Page 讀取

public class IndexModel : PageModel
{
    public void OnGet()
    {
        var message = HttpContext.Request.PathBase;
    }
}

從Razer Page 的cshtml 讀取

@page
@model IndexModel
@{
    var message = HttpContext.Request.PathBase;
}

從 Controller 讀取

public class HomeController : Controller
{
    public IActionResult About()
    {
        var pathBase = HttpContext.Request.PathBase;
        return View();
    }
}

從 Minimal API 讀取

app.MapGet("/", (HttpContext context) => context.Response.WriteAsync("Hello World"));

修改 HttpContext.Request

HttpContext.Request 可以獲取客戶端發(fā)來的 HttpRequest 請求，并且可以修改其中的值，包括：

• HttpRequest.Path
• HttpRequest.Method
• HttpRequest.Headers
• HttpRequest.RouteValues
• HttpRequest.Query
• HttpRequest.ReadFormAsync()
• HttpRequest.Body

例如下面的代碼：

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/", (HttpRequest request) =>
{
    var userAgent = request.Headers.UserAgent;
    var customHeader = request.Headers["x-custom-header"];
    return Results.Ok(new { userAgent = userAgent, customHeader = customHeader });
});

app.Run();

修改 HttpContext.Response

除了能修改接收到的 HttpRequest，返回給客戶端的 Response也可以修改。包括：

• HttpResponse.StatusCode
• HttpResponse.ContentType
• HttpResponse.Headers
• HttpResponse.Body

例子代碼如下：

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

app.MapGet("/", (HttpResponse response) =>
{
    response.Headers.CacheControl = "no-cache";
    response.Headers["x-custom-header"] = "Custom value";
    return Results.File(File.OpenRead("helloworld.txt"));
});

app.Run();

設(shè)置 Response 尾巴

HTTP/2 和 HTTP/3 支持 Response 尾巴，可以在返回 Response 后設(shè)置Response 尾巴。
例子代碼如下：

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();
app.MapGet("/", (HttpResponse response) =>
{
    // Write body
    response.WriteAsync("Hello world");
    if (response.SupportsTrailers())
    {
        response.AppendTrailer("trailername", "TrailerValue");
    }
});
app.Run();

終止 HttpRequest

HttpContext.RequestAborted cancellation token 可以用于通知HttpRequest 已經(jīng)被終止。
在請求時：文章來源地址http://www.zghlxwxcb.cn/news/detail-680887.html

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

var httpClient = new HttpClient();
app.MapPost("/books/{bookId}", async (int bookId, HttpContext context) =>
{
    var stream = await httpClient.GetStreamAsync(
        $"http://consoto/books/{bookId}.json", context.RequestAborted);
    return Results.Stream(stream, "application/json");
});
app.Run();

到了這里，關(guān)于ASP.NET Core 的 HttpContex的文章就介紹完了。如果您還想了解更多內(nèi)容，請在右上角搜索TOY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！