func handler(w http.ResponseWriter, r *http.Request) {
    r.ParseForm()
    username := r.Form.Get("username")
    email := r.Form.Get("email")

    user := User{Username: username, Email: email}
    // 处理 user 结构
}

func bind(formValues url.Values, obj interface{}) error {
    v := reflect.ValueOf(obj).Elem()
    t := v.Type()

    for i := 0; i < v.NumField(); i++ {
        field := v.Field(i)
        fieldType := t.Field(i)
        formName := fieldType.Tag.Get("form")
        if formName == "" {
            formName = fieldType.Name
        }

        value := formValues.Get(formName)
        if value == "" {
            continue
        }

        switch field.Kind() {
        case reflect.String:
            field.SetString(value)
        case reflect.Int:
            intValue, _ := strconv.Atoi(value)
            field.SetInt(int64(intValue))
        // 其他类型可继续扩展
        }
    }
    return nil
}

type User struct {
    Username string `schema:"username"`
    Age      int    `schema:"age"`
}

func handler(w http.ResponseWriter, r *http.Request) {
    var user User
    decoder := schema.NewDecoder()
    r.ParseForm()
    decoder.Decode(&user, r.PostForm)
    // user 已被自动填充
}

c.Bind(&user) // 自动绑定 JSON 或表单