表單資料通常會使用「媒體類型」`application/x-www-form-urlencoded` 進行編碼。

但當表單包含檔案時，會使用 `multipart/form-data`。你會在下一章閱讀如何處理檔案。

若想進一步了解這些編碼與表單欄位，請參考 [<abbr title="Mozilla Developer Network - Mozilla 開發者網路">MDN</abbr> web docs 的 `POST`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST)。

///

/// warning

你可以在一個 *路徑操作（path operation）* 中宣告多個 `Form` 參數，但不能同時再宣告期望以 JSON 接收的 `Body` 欄位，因為該請求的本文會使用 `application/x-www-form-urlencoded` 編碼，而不是 `application/json`。

      .assertLogMatch(Regex("""callEnd"""))
      .assertNoMoreLogs()
  }

  @Test
  fun post() {
    assumeNotWindows()
    server.enqueue(MockResponse())
    client.newCall(request().post("Hello!".toRequestBody(PLAIN)).build()).execute()
    logRecorder
      .assertLogMatch(Regex("""callStart: Request\{method=POST, url=$url\}"""))
      .assertLogMatch(Regex("""proxySelectStart: $url"""))

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()]):

Der Benutzer Ihrer API (ein externer Entwickler) erstellt mit einem POST-Request eine Rechnung in Ihrer API.

Dann wird Ihre API (stellen wir uns vor):

* die Rechnung an einen Kunden des externen Entwicklers senden.
* das Geld einsammeln.
* eine Benachrichtigung an den API-Benutzer (den externen Entwickler) zurücksenden.

app = FastAPI()


class BaseUser(BaseModel):
    username: str
    email: EmailStr
    full_name: str | None = None


class UserIn(BaseUser):
    password: str


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

---
name: Feature request
about: Suggest an idea for this project
title: ''
labels: ''
assignees: ''

---

---
name: Feature request
about: Suggest an idea for this project
title: ''
labels: ''
assignees: ''

---

app = FastAPI()


class UserIn(BaseModel):
    username: str
    password: str
    email: EmailStr
    full_name: str | None = None


# Don't do this in production!
@app.post("/user/")
async def create_user(user: UserIn) -> UserIn:

from typing import Annotated

from fastapi import FastAPI, File, Form, UploadFile

app = FastAPI()


@app.post("/files/")
async def create_file(
    file: Annotated[bytes, File()],
    fileb: Annotated[UploadFile, File()],
    token: Annotated[str, Form()],
):
    return {
        "file_size": len(file),
        "token": token,
        "fileb_content_type": fileb.content_type,

    string.getChars(0, len, strCopy, 0);

    char[] array = new char[len * count];

    int strCopyLen = len;
    int pos = 0;
    while (count != 0) {
      if ((count & 1) != 0) {
        System.arraycopy(strCopy, 0, array, pos, strCopyLen);
        pos += strCopyLen;
      }
      count >>= 1;
      if (count != 0) {
        System.arraycopy(strCopy, 0, strCopy, strCopyLen, strCopyLen);