Playframework [Scala]：如何在视图中显示图像文件/采用类型参数的 [error] 类 MultipartFormData

我想在视图中显示上传的文件；但是我不知道该怎么做。

首先我试图传递multipartFormData给视图文件，但发生了错误：

类 MultipartFormData 接受类型参数

问题是以下几行：

@(user:models.User,file:MultipartFormData,fileOption:Option[Long])(隐式请求:RequestHeader,messages:Messages,webJarAssets:WebJarAssets)

在我的控制器类 ( FileUploadController.scala) 中，我有以下内容：

  type FilePartHandler[A] = FileInfo => Accumulator[ByteString, FilePart[A]]

  def handleFilePartAsFile: FilePartHandler[File] = {
    case FileInfo(partName, filename, contentType) =>
      val attr = PosixFilePermissions.asFileAttribute(util.EnumSet.of(OWNER_READ, OWNER_WRITE))
      val path: Path = Files.createTempFile("multipartBody", "tempFile", attr)

      if (Files.notExists(path)) Files.createFile(path)

      val file = path.toFile

      val fileSink: Sink[ByteString, Future[IOResult]] = FileIO.toPath(path)
      val accumulator: Accumulator[ByteString, IOResult] = Accumulator(fileSink)
      accumulator.map {
        case IOResult(count, status) =>
          logger.info(s"count = $count, status = $status")
          FilePart(partName, filename, contentType, file)
      }
  }

  def upload = silhouette.SecuredAction.async(parse.multipartFormData(handleFilePartAsFile)) { implicit request =>

    val fileOption = request.body.file("picName").map {

      case FilePart(key, filename, contentType, file) =>
        logger.info(s"key = ${key}, filename = ${filename}, contentType = ${contentType}, file = $file")

        val data = operateOnTempFile(file)

    FileUploadFormSupport.picsave(key, filename, contentType, file)

        data

    }

    Future.successful(Ok(views.html.fileUpload2(request.identity, request.body.file("picName"), fileOption)))
    }
}

在我的视图文件 ( fileupload2.scala.html) 中，我有以下内容：

@(user: models.User, file: MultipartFormData, fileOption: Option[Long])(implicit request: RequestHeader, messages: Messages, webJarAssets: WebJarAssets)

@import b3.inline.fieldConstructor

@main(Messages("fileupload.title"), Some(user)) {

   <div class="user col-md-6 col-md-offset-3">
        <div class="row data">
            <div class="col-md-12">
                <div class="row">

                <img src="file">
                    <p class="col-md-6"><strong>@Messages("file.name"):</strong></p>
                    <p class="col-md-6">file size is @fileOption.getOrElse("None")</p>
                </div>
            </div>
        </div>
    </div>

}