// Two-byte form.
        if (index == end) {
          return false;
        }
        // Simultaneously check for illegal trailing-byte in leading position
        // and overlong 2-byte form.
        if (byte1 < (byte) 0xC2 || bytes[index++] > (byte) 0xBF) {
          return false;
        }
      } else if (byte1 < (byte) 0xF0) {
        // Three-byte form.
        if (index + 1 >= end) {

# 请求表单与文件

FastAPI 支持同时使用 `File` 和 `Form` 定义文件和表单字段。

/// info | "说明"

接收上传文件或表单数据，要预先安装 <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>。

例如，`pip install python-multipart`。

///

## 导入 `File` 与 `Form`

```Python hl_lines="1"
{!../../docs_src/request_forms_and_files/tutorial001.py!}
```

## 定义 `File` 与 `Form` 参数

创建文件和表单参数的方式与 `Body` 和 `Query` 一样：

    /**
     * The media-type multipart/form-data follows the rules of all multipart MIME data streams as
     * outlined in RFC 2046. In forms, there are a series of fields to be supplied by the user who
     * fills out the form. Each field has a name. Within a given form, the names are unique.
     */
    @JvmField
    val FORM = "multipart/form-data".toMediaType()

      """
      |--AaB03x
      |Content-Disposition: form-data; name="field with spaces"; filename="filename with spaces.txt"
      |Content-Type: text/plain; charset=utf-8
      |
      |okay
      |--AaB03x
      |Content-Disposition: form-data; name="field with %22"
      |
      |"
      |--AaB03x
      |Content-Disposition: form-data; name="field with %22"
      |
      |%22
      |--AaB03x

package tests_test

import (
	"testing"

	"gorm.io/gorm"
	. "gorm.io/gorm/utils/tests"
)

func TestUpdateBelongsTo(t *testing.T) {
	user := *GetUser("update-belongs-to", Config{})

	if err := DB.Create(&user).Error; err != nil {
		t.Fatalf("errors happened when create: %v", err)
	}

	user.Company = Company{Name: "company-belongs-to-association"}
	user.Manager = &User{Name: "manager-belongs-to-association"}

package callbacks

import (
	"gorm.io/gorm"
)

func BeginTransaction(db *gorm.DB) {
	if !db.Config.SkipDefaultTransaction && db.Error == nil {
		if tx := db.Begin(); tx.Error == nil {
			db.Statement.ConnPool = tx.Statement.ConnPool
			db.InstanceSet("gorm:started_transaction", true)
		} else if tx.Error == gorm.ErrInvalidTransaction {
			tx.Error = nil
		} else {
			db.Error = tx.Error
		}
	}
}

  ...

Sie können gleichzeitig Dateien und Formulardaten mit `File` und `Form` definieren.

/// info

Um hochgeladene Dateien und/oder Formulardaten zu empfangen, installieren Sie zuerst <a href="https://andrew-d.github.io/python-multipart/" class="external-link" target="_blank">`python-multipart`</a>.

Z. B. `pip install python-multipart`.

///

## `File` und `Form` importieren

//// tab | Python 3.9+

```Python hl_lines="3"

    }

    @Execute
    @Secured({ ROLE })
    public HtmlResponse upgradeFrom(final UpgradeForm form) {
        validate(form, messages -> {}, this::asIndexHtml);
        verifyToken(this::asIndexHtml);

        if (VERSION_13_0.equals(form.targetVersion)) {
            try {
                upgradeFrom13_0();
                upgradeFrom13_1();
                upgradeFrom13_2();

                                            <la:text styleId="urlExpr" property="urlExpr" styleClass="form-control"/>
                                        </div>
                                    </div>
                                    <div class="form-group row">
                                        <label for="boostExpr" class="col-sm-2 text-sm-right col-form-label"><la:message