EPiServer 11:编程转换媒体类型

Question

是否有人试图以编程方式在EPiServer中转换媒体文件类型？

我们有一个为图像建模的类型，ImageFile，以及一个通过插件添加的类型。我们不使用插件添加的类型，但是我们发现上传的图像有时会被创建为错误的类型。我希望找到如何进行转换，以便我可以运行一个预定的作业，批量转换他们，然后删除插件。

到目前为止，我可以编程地将A复制为B类型，然后删除A。我真正想做的是将A转换为B，以实现无缝转换。

我尝试的第一件事是将图像复制为适当的类型，但结果为null。

var media = _contentRepository.Service.GetDescendents(SiteDefinition.Current.GlobalAssetsRoot)
                .Where(i => _contentRepository.Service.Get<IContent>(i) is MediaData);
var imageFileTypeId = new ImageFile().ContentTypeID;
foreach (var img in media)
{
    if (img.Get<IContent>() is GcEpiImageFile)
    {
         count++ // for summary
         var item = _contentLoader.Service.Get<GcEpiImageFile>(img.Get<IContent>().ContentLink);
         var cloneItem = item.CreateWritableClone() as ImageFile;
         if (cloneItem == null) 
         {
             var msg = $"{item.Name}: {item.ContentLink.ID} came up null";
             OnStatusChanged(msg);
             summaryMessage.AppendLine(msg);
             continue;
         }
         cloneItem.ContentTypeID = imageFileTypeId;
         _contentRepository.Service.Save(cloneItem, SaveAction.Publish, AccessLevel.NoAccess);

    }

接下来，我尝试将其克隆为基类ImageData，它似乎创建了对象，但在保存时抛出对象引用，而不是设置为对象异常的实例。

var media = _contentRepository.Service.GetDescendents(SiteDefinition.Current.GlobalAssetsRoot)
                .Where(i => _contentRepository.Service.Get<IContent>(i) is MediaData);
var imageFileTypeId = new ImageFile().ContentTypeID;
foreach (var img in media)
{
    if (img.Get<IContent>() is GcEpiImageFile)
    {
         count++ // for summary
         var item = _contentLoader.Service.Get<GcEpiImageFile>(img.Get<IContent>().ContentLink);
         var cloneItem = item.CreateWritableClone() as ImageData;
         if (cloneItem == null) 
         {
             var msg = $"{item.Name}: {item.ContentLink.ID} came up null";
             OnStatusChanged(msg);
             summaryMessage.AppendLine(msg);
             continue;
         }
         try
         { 
             cloneItem.ContentTypeID = imageFileTypeId;
         }
         catch (Exception ex)
         {
             summaryMessage.AppendLine($"exception triggered by id assignment {ex.Message}<br />{ex.InnerException}");
         }
         try
         { 
             _contentRepository.Service.Save(cloneItem, SaveAction.Publish, AccessLevel.NoAccess);
         }
         catch (Exception ex)
         {
             summaryMessage.AppendLine(
                            $"exception triggered by save {ex.Message}<br />{ex.InnerException}");
         }
    }

这是我的堆栈跟踪：

Object reference not set to an instance of an object.
at EPiServer.Validation.Internal.RoutingSegmentValidator.Validate(IContent instance) at

EPiServer.Validation.Internal.ContextValidatorWrapper`2.Validate(Object instance, Object context) 

at EPiServer.Validation.Internal.ValidationService.ValidateRecursively(Object instance, Object context, HashSet`1 visitedInstances) 

at EPiServer.Validation.Internal.ValidationService.Validate[T](Object instance, T context) 

at EPiServer.Core.ContentProvider.Validate(IContent content, ContentSaveValidationContext saveValidationContext) 

at EPiServer.Core.Internal.DefaultContentRepository.Save(IContent content, SaveAction action, AccessLevel access) at Web.Business.ScheduledJobs.ImageConversion.Execute()

任何想法、帮助、指导都将不胜感激。

Answer 1

在EPiServer开发者论坛上向约翰·克伦伯格致敬，感谢他的帮助。

BEGIN TRANSACTION [ConvertTransaction]
BEGIN TRY
  DECLARE @FromPropertyID1 int
  DECLARE @ToPropertyID1 int
  DECLARE @FromPropertyID2 int
  DECLARE @ToPropertyID2 int
  DECLARE @FromPropertyID3 int
  DECLARE @ToPropertyID3 int

  DECLARE @RC int
  DECLARE @PageID int
  DECLARE @FromPageType int
  DECLARE @ToPageType int
  DECLARE @Recursive bit
  DECLARE @IsTest bit

  SELECT @PageID = 1
#get your type ids from content type guid
  SELECT @FromPageType = pkID FROM tblContentType WHERE ContentTypeGUID = 'guid of the media type being changed'
  SELECT @ToPageType = pkID FROM tblContentType WHERE ContentTypeGUID = 'guid of the media type it is being change to'


#mapping properties THIS IS IMPORTANT!!!

  SELECT @FromPropertyID1 = pkID FROM tblPropertyDefinition WHERE fkContentTypeID = @FromPageType AND [Name] = 'Copyright'
  SELECT @FromPropertyID2 = pkID FROM tblPropertyDefinition WHERE fkContentTypeID = @FromPageType AND [Name] = 'Description'
  SELECT @FromPropertyID3 = pkID FROM tblPropertyDefinition WHERE fkContentTypeID = @FromPageType AND [Name] = 'Notes'

  SELECT @ToPropertyID1 = pkID FROM tblPropertyDefinition WHERE fkContentTypeID = @ToPageType AND [Name] = 'Copyright'
  SELECT @ToPropertyID2 = pkID FROM tblPropertyDefinition WHERE fkContentTypeID = @ToPageType AND [Name] = 'Alt Text'
  SELECT @ToPropertyID3 = pkID FROM tblPropertyDefinition WHERE fkContentTypeID = @ToPageType AND [Name] = 'Notes'

  SET @Recursive = 1
  SET @IsTest = 0

  print @PageID
  print @FromPageType
  print @ToPageType

  DECLARE @MasterLanguageID int

  SET @MasterLanguageID = 8

  EXECUTE @RC = [dbo].[netConvertPropertyForPageType]
     @PageID
    ,@FromPageType
    ,@FromPropertyID1
    ,@ToPropertyID1
    ,@Recursive
    ,@MasterLanguageID
    ,@IsTest

  print @RC

  EXECUTE @RC = [dbo].[netConvertPropertyForPageType]
     @PageID
    ,@FromPageType
    ,@FromPropertyID2
    ,@ToPropertyID2
    ,@Recursive
    ,@MasterLanguageID
    ,@IsTest

  print @RC

  EXECUTE @RC = [dbo].[netConvertPropertyForPageType]
     @PageID
    ,@FromPageType
    ,@FromPropertyID3
    ,@ToPropertyID3
    ,@Recursive
    ,@MasterLanguageID
    ,@IsTest

  print @RC

  EXECUTE @RC = [dbo].[netConvertPageType]
     @PageID
    ,@FromPageType
    ,@ToPageType
    ,@Recursive
    ,@IsTest

  print @RC

  COMMIT TRANSACTION [ConvertTransaction]
END TRY
BEGIN CATCH
  ROLLBACK TRANSACTION [ConvertTransaction]
END CATCH

-- Run separately
DECLARE @FromPageType int
SELECT @FromPageType = pkID FROM tblContentType WHERE ContentTypeGUID = '0a89e464-56d4-449f-aea8-2bf774ab8730'
EXECUTE netContentTypeDelete @ContentTypeID = @FromPageType

备注如果源类型比目标类型具有更多的属性，则可能需要向目标添加属性。在第一次运行时，我能够转换类型，但无法删除目标类型。