Topic                string         `json:"topic"`
	QoS                  byte           `json:"qos"`
	User                 string         `json:"username"`
	Password             string         `json:"password"`
	MaxReconnectInterval time.Duration  `json:"reconnectInterval"`
	KeepAlive            time.Duration  `json:"keepAliveInterval"`
	RootCAs              *x509.CertPool `json:"-"`

```

Por exemplo, em uma das maneiras que a especificação OAuth2 pode ser usada (chamada "fluxo de senha"), é necessário enviar um `username` e uma `password` como campos do formulário.

A <abbr title="especificação">spec</abbr> exige que os campos sejam exatamente nomeados como `username` e `password` e sejam enviados como campos de formulário, não JSON.

创建表单（`Form`）参数的方式与 `Body` 和 `Query` 一样：

```Python hl_lines="7"
{!../../docs_src/request_forms/tutorial001.py!}
```

例如，OAuth2 规范的 "密码流" 模式规定要通过表单字段发送 `username` 和 `password`。

<abbr title="specification">该规范</abbr>要求字段必须命名为 `username` 和 `password`，并通过表单字段发送，不能用 JSON。

使用 `Form` 可以声明与 `Body` （及 `Query`、`Path`、`Cookie`）相同的元数据和验证。

/// info | "说明"

`Form` 是直接继承自 `Body` 的类。

///

/// tip | "提示"

#
# o driver   -- The class name of JDBC-Driver.
# 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:{

        with:
          username: ${{ secrets.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      -
        name: Login to GCR
        uses: docker/login-action@9780b0c442fbb1117ed29e0efdff1e18412f7567 # v3.3.0
        with:
          registry: gcr.io
          username: _json_key
          password: ${{ secrets.GCP_CREDS }}
      -
        name: Generate variables for cache busting and tag naming

        return Base64.getEncoder().encodeToString(type1Message.toByteArray());
    }

    @Override
    public String generateType3Msg(final String username, final String password, final String domain, final String workstation,
            final String challenge) throws NTLMEngineException {
        Type2Message type2Message;
        try {

from fastapi import FastAPI, Form
from pydantic import BaseModel

app = FastAPI()


class FormData(BaseModel):
    username: str
    password: str

    class Config:
        extra = "forbid"


@app.post("/login/")
async def login(data: FormData = Form()):

from fastapi import FastAPI, Form
from pydantic import BaseModel
from typing_extensions import Annotated

app = FastAPI()


class FormData(BaseModel):
    username: str
    password: str
    model_config = {"extra": "forbid"}


@app.post("/login/")
async def login(data: Annotated[FormData, Form()]):

from typing import Annotated

from fastapi import FastAPI, Form
from pydantic import BaseModel

app = FastAPI()


class FormData(BaseModel):
    username: str
    password: str
    model_config = {"extra": "forbid"}


@app.post("/login/")
async def login(data: Annotated[FormData, Form()]):

from pydantic import BaseModel, EmailStr

app = FastAPI()


class BaseUser(BaseModel):
    username: str
    email: EmailStr
    full_name: Union[str, None] = None


class UserIn(BaseUser):
    password: str


@app.post("/user/")
async def create_user(user: UserIn) -> BaseUser: