import warnings

import pytest
from fastapi import APIRouter, Depends, FastAPI, Response
from fastapi.responses import JSONResponse
from fastapi.testclient import TestClient


class ResponseLevel0(JSONResponse):
    media_type = "application/x-level-0"


class ResponseLevel1(JSONResponse):
    media_type = "application/x-level-1"


class ResponseLevel2(JSONResponse):
    media_type = "application/x-level-2"

在高级使用场景中，如果不想使用「缓存」值，而是为需要在同一请求的每一步操作（多次）中都实际调用依赖项，可以把 `Depends` 的参数 `use_cache` 的值设置为 `False` :

```Python hl_lines="1"
async def needy_dependency(fresh_value: str = Depends(get_value, use_cache=False)):
    return {"fresh_value": fresh_value}
```

## 小结

千万别被本章里这些花里胡哨的词藻吓倒了，其实**依赖注入**系统非常简单。

依赖注入无非是与*路径操作函数*一样的函数罢了。

# o url      -- The URL for connecting database.
# o schema   -- The schema name.
# o user     -- The database user name.
# o password -- The database password.
# o propertiesMap -- The properties that depends on the database.
# o variousMap    -- The various settings about JDBC task.
#
# *The line that starts with '#' means comment-out.
#
map:{
    ; driver   = org.h2.Driver

///

`oauth2_scheme` 🔢 👐 `OAuth2PasswordBearer`, ✋️ ⚫️ "🇧🇲".

⚫️ 💪 🤙:

```Python
oauth2_scheme(some, parameters)
```

, ⚫️ 💪 ⚙️ ⏮️ `Depends`.

### ⚙️ ⚫️

🔜 👆 💪 🚶‍♀️ 👈 `oauth2_scheme` 🔗 ⏮️ `Depends`.

```Python hl_lines="10"
{!../../docs_src/security/tutorial001.py!}
```

👉 🔗 🔜 🚚 `str` 👈 🛠️ 🔢 `token` *➡ 🛠️ 🔢*.

<img src="/img/tutorial/websockets/image03.png">

您可以发送（和接收）多条消息：

<img src="/img/tutorial/websockets/image04.png">

所有这些消息都将使用同一个 WebSocket 连

接。

## 使用 `Depends` 和其他依赖项

在 WebSocket 端点中，您可以从 `fastapi` 导入并使用以下内容：

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

它们的工作方式与其他 FastAPI 端点/ *路径操作* 相同：

//// tab | Python 3.10+

```Python hl_lines="68-69  82"

	formatMetaVersionV1 = "1"
)

// format.json currently has the format:
// {
//   "version": "1",
//   "format": "XXXXX",
//   "XXXXX": {
//
//   }
// }
// Here "XXXXX" depends on the backend, currently we have "fs" and "xl" implementations.
// formatMetaV1 should be inherited by backend format structs. Please look at format-fs.go
// and format-xl.go for details.

<img src="/img/tutorial/websockets/image04.png">

Und alle verwenden dieselbe WebSocket-Verbindung.

## Verwendung von `Depends` und anderen

In WebSocket-Endpunkten können Sie Folgendes aus `fastapi` importieren und verwenden:

* `Depends`
* `Security`
* `Cookie`
* `Header`
* `Path`
* `Query`

而且你还可以根据你的需要响应不同的对象，比如常用的 `dict`，数据库model等。

如果你定义了 `response_model`，程序会自动根据`response_model`来过滤和转换你响应的对象。

**FastAPI** 会使用这个 *临时* 响应对象去装在这些cookies信息 (同样还有headers和状态码等信息), 最终会将这些信息和通过`response_model`转化过的数据合并到最终的响应里。

你也可以在depend中定义`Response`参数，并设置cookie和header。

## 直接响应 `Response`

你还可以在直接响应`Response`时直接创建cookies。

你可以参考[Return a Response Directly](response-directly.md){.internal-link target=_blank}来创建response

然后设置Cookies，并返回：

			// that broke people during the Go 1.8 testing
			// period. People depend on it being 0 I
			// guess. Maybe retry later. See Issue 18117.
		}
		// For client requests, Request.ContentLength of 0
		// means either actually 0, or unknown. The only way
		// to explicitly say that the ContentLength is zero is
		// to set the Body to nil. But turns out too much code
		// depends on NewRequest returning a non-nil Body,

Pode ser chamada de:

```Python
oauth2_scheme(some, parameters)
```

Então, pode ser usado com `Depends`.

## Use-o

Agora você pode passar aquele `oauth2_scheme` em uma dependência com `Depends`.

```Python hl_lines="10"
{!../../docs_src/security/tutorial001.py!}
```