///

## 返回自定义 `Response`

上面的例子展示了需要的所有部分，但还不够实用，因为你本可以只是直接返回 `item`，而**FastAPI** 默认帮你把这个 `item` 放到 `JSONResponse` 中，又默认将其转换成了 `dict`等等。

现在，让我们看看你如何才能返回一个自定义的响应。

假设你想要返回一个 <a href="https://en.wikipedia.org/wiki/XML" class="external-link" target="_blank">XML</a> 响应。

你可以把你的 XML 内容放到一个字符串中，放到一个 `Response` 中，然后返回。

{* ../../docs_src/response_directly/tutorial002.py hl[1,18] *}

## 说明

for it.

If we decide to pursue a feature request, it will go through a thorough process
of API design and review. Any code should come after this.

[APIs]: https://en.wikipedia.org/wiki/API
[issue]: https://github.com/google/guava/issues

Pull requests
-------------

Unless the change is a trivial fix such as for a typo, it's generally best to

Da die Testfunktion jetzt asynchron ist, können Sie in Ihren Tests neben dem Senden von Requests an Ihre FastAPI-Anwendung jetzt auch andere `async`-Funktionen aufrufen (und `await`en), genau so, wie Sie diese an anderer Stelle in Ihrem Code aufrufen würden.

/// tip | Tipp

Starlette (and **FastAPI**) are based on <a href="https://anyio.readthedocs.io/en/stable/" class="external-link" target="_blank">AnyIO</a>, which makes it compatible with both Python's standard library <a href="https://docs.python.org/3/library/asyncio-task.html" class="external-link" target="_blank">asyncio</a> and <a href="https://trio.readthedocs.io/en/stable/" class="external-link" target="_blank">Trio</a>.

   * `Synchronized` doesn't guarantee that it will hold the mutex for those calls because callers
   * are responsible for taking the mutex themselves:
   * https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/util/Collections.html#synchronizedCollection(java.util.Collection)
   *
   * Similarly, we avoid having those methods *implemented* in terms of *other* TestSet methods

/// tip

To know more about each status code and which code is for what, check the <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Status" class="external-link" target="_blank"><abbr title="Mozilla Developer Network">MDN</abbr> documentation about HTTP status codes</a>.

///

Se você quiser ler mais sobre essas codificações e campos de formulário, vá para o <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network – Rede de Desenvolvedores da Mozilla">MDN</abbr> web docs para <code>POST</code></a>.

///

/// warning | Atenção

Starlette (e **FastAPI**) são baseados no <a href="https://anyio.readthedocs.io/en/stable/" class="external-link" target="_blank">AnyIO</a>, o que o torna compatível com ambos o <a href="https://docs.python.org/3/library/asyncio-task.html" class="external-link" target="_blank">asyncio</a> da biblioteca padrão do Python, e o <a href="https://trio.readthedocs.io/en/stable/" class="external-link" target="_blank">Trio</a>.

Заголовки прокси:

* <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-For" class="external-link" target="_blank">X-Forwarded-For</a>
* <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/X-Forwarded-Proto" class="external-link" target="_blank">X-Forwarded-Proto</a>

    * 然后它将返回由相应的*路径操作*生成的 `response`.
* 然后你可以在返回 `response` 前进一步修改它.

{* ../../docs_src/middleware/tutorial001.py hl[8:9,11,14] *}

/// tip

请记住可以 <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">用'X-' 前缀</a>添加专有自定义请求头.