اما اگر هدرهای سفارشی دارید که می‌خواهید مرورگر کاربر بتواند آنها را ببیند، باید آنها را با استفاده از پارامتر `expose_headers` که در مستندات <a href="https://www.starlette.io/middleware/#corsmiddleware" class="external-link" target="_blank">CORS از Starlette</a> توضیح داده شده است، به پیکربندی CORS خود اضافه کنید.

///

/// توجه | "جزئیات فنی"

شما همچنین می‌توانید از `from starlette.requests import Request` استفاده کنید.

    * Pydantic ermöglicht auch die Darstellung als „ISO 8601 Zeitdifferenz-Kodierung“, <a href="https://docs.pydantic.dev/1.10/usage/exporting_models/#json_encoders" class="external-link" target="_blank">Weitere Informationen finden Sie in der Dokumentation</a>.
* `frozenset`:
    * Wird in Requests und Responses wie ein `set` behandelt:

## Install dependencies

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and install `jinja2`:

<div class="termy">

```console
$ pip install jinja2

---> 100%
```

</div>

## Using `Jinja2Templates`

* Import `Jinja2Templates`.

Aqui veremos um exemplo usando <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a>.

**SQLModel** é construído sobre <a href="https://www.sqlalchemy.org/" class="external-link" target="_blank">SQLAlchemy</a> e Pydantic. Ele foi criado pelo mesmo autor do **FastAPI** para ser o par perfeito para aplicações **FastAPI** que precisam usar **bancos de dados SQL**.

# Configurar Swagger UI

Você pode configurar alguns <a href="https://swagger.io/docs/open-source-tools/swagger-ui/usage/configuration/" class="external-link" target="_blank">parâmetros extras da UI do Swagger</a>.

Para configurá-los, passe o argumento `swagger_ui_parameters` ao criar o objeto de aplicativo `FastAPI()` ou para a função `get_swagger_ui_html()`.

`swagger_ui_parameters` recebe um dicionário com as configurações passadas diretamente para o Swagger UI.

필요에 따라 응용 프로그램이 시작되기 전이나 종료될 때 실행되는 이벤트 핸들러(함수)를 정의할 수 있습니다.

이 함수들은 `async def` 또는 평범하게 `def`으로 선언할 수 있습니다.

/// warning | "경고"

이벤트 핸들러는 주 응용 프로그램에서만 작동합니다. [하위 응용 프로그램 - 마운트](./sub-applications.md){.internal-link target=_blank}에서는 작동하지 않습니다.

///

## `startup` 이벤트

응용 프로그램을 시작하기 전에 실행하려는 함수를 "startup" 이벤트로 선언합니다:

```Python hl_lines="8"
{!../../docs_src/events/tutorial001.py!}
```

            } else {
                try {
                    final String target = String.valueOf(c);
                    final String converted = URLEncoder.encode(target, Constants.UTF_8);
                    if (target.equals(converted)) {
                        encodedBuf.append(Base64.getUrlEncoder().encodeToString(target.getBytes(Constants.CHARSET_UTF_8)));
                    } else {

更多细节查看 <a href="https://www.starlette.io/background/" class="external-link" target="_blank">Starlette's official docs for Background Tasks</a>.

## 告诫

如果您需要执行繁重的后台计算，并且不一定需要由同一进程运行（例如，您不需要共享内存、变量等），那么使用其他更大的工具（如 <a href="https://docs.celeryq.dev" class="external-link" target="_blank">Celery</a>）可能更好。

它们往往需要更复杂的配置，即消息/作业队列管理器，如RabbitMQ或Redis，但它们允许您在多个进程中运行后台任务，甚至是在多个服务器中。

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test

import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.RetentionPolicy.CLASS;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Signifies that a test should not be run under Android. This annotation is respected only by our
 * Google-internal Android suite generators. Note that those generators also suppress any test