Ruby on rails 如何在rails控制器中使用参数

下面是传递给rails控制器的参数

Parameters: {"file"=>#<ActionDispatch::Http::UploadedFile:0x007f6244989100 @tempfile=#<Tempfile:/tmp/RackMultipart20151109-3635-1y6e4wr.mp3>,
@original_filename="07 - Barfi - Ala Barfi! (Version 2) [DM].mp3",
@content_type="audio/mp3", @headers="Content-Disposition: form-data; name=\"file\"; filename=\"07 - Barfi - Ala Barfi! (Version 2) [DM].mp3\"\r\nContent-Type: audio/mp3\r\n">, 
"event_id"=>"19"}

下面是我的播放列表模式

  create_table "playlists", force: :cascade do |t|
    t.string   "file",       limit: 255
    t.integer  "event_id",   limit: 4
    t.datetime "created_at",             null: false
    t.datetime "updated_at",             null: false
    t.string   "name",       limit: 255
  end

但“我的名字”列显示为空

下面是上面的服务器端代码

Started POST "/events/19/playlists" for 127.0.0.1 at 2015-11-09 18:06:17 +0530

Processing by Api::V1::PlaylistsController#create as JSON

Parameters: {"file"=>#<ActionDispatch::Http::UploadedFile:0x007f6244989100 @tempfile=#<Tempfile:/tmp/RackMultipart20151109-3635-1y6e4wr.mp3>, @original_filename="07 - Barfi - Ala Barfi! (Version 2) [DM].mp3", @content_type="audio/mp3", @headers="Content-Disposition: form-data; name=\"file\"; filename=\"07 - Barfi - Ala Barfi! (Version 2) [DM].mp3\"\r\nContent-Type: audio/mp3\r\n">, "event_id"=>"19"}

Can't verify CSRF token authenticity

Event Load (0.2ms)  SELECT  `events`.* FROM `events` WHERE `events`.`id` = 19 LIMIT 1
Unpermitted parameters: format, event_id
Unpermitted parameters: format, event_id

(0.2ms)  BEGIN
SQL (0.4ms)  INSERT INTO `playlists` (`file`, `event_id`, `created_at`, `updated_at`) VALUES ('07_-_Barfi_-_Ala_Barfi___Version_2___DM_.mp3', 19, '2015-11-09 12:36:17', '2015-11-09 12:36:17')
   (55.3ms)  COMMIT

Completed 200 OK in 161ms (Views: 1.4ms | ActiveRecord: 60.3ms)

---

我不知道为什么sql没有在上面的服务器端代码中插入播放列表表的“名称”列。

在参数中传递的文件属性实际上包含您需要的大部分数据@原始文件名是正在上载的文件的实例变量

您可以尝试使用控制器的强参数部分，并尝试将其修改为如下所示：

def playlist_params
  params.permit(file: [])
end

def create
  event = Event.find(params[:event_id])
  file = params[:file]
  playlist = event.playlists.create(file: file, name: file.original_filename)
  render json: event
end

然后，当您要保存文件时，您可以将代码改为如下所示：

def create
  event = Event.find(params[:event_id])
  file = playlist_params[:file]
  playlist = event.playlists.create(file: file, name: file.original_filename)
  render json: event
end

您可能会说您并不真的需要播放列表参数，您可以这样访问参数[：file]：

def playlist_params
  params.permit(file: [])
end

def create
  event = Event.find(params[:event_id])
  file = params[:file]
  playlist = event.playlists.create(file: file, name: file.original_filename)
  render json: event
end