c# - 将 OLE 对象从一张幻灯片复制到另一张幻灯片会损坏生成的 PowerPoint

Question

我有将一张 PowerPoint 幻灯片的内容复制到另一张幻灯片的代码。下面是如何处理图像的示例。

foreach (OpenXmlElement element in sourceSlide.CommonSlideData.ShapeTree.ChildElements.ToList())
{
    string elementType = element.GetType().ToString();

    if (elementType.EndsWith(".Picture"))
    {
        // Deep clone the element.
        elementClone = element.CloneNode(true);
        var picture = (Picture)elementClone;

        // Get the picture's original rId
        var blip = picture.BlipFill.Blip;
        string rId = blip.Embed.Value;
        
        // Retrieve the ImagePart from the original slide by rId
        ImagePart sourceImagePart = (ImagePart)sourceSlide.SlidePart.GetPartById(rId);

        // Add the image part to the new slide, letting OpenXml generate the new rId
        ImagePart targetImagePart = targetSlidePart.AddImagePart(sourceImagePart.ContentType);

        // And copy the image data.
        targetImagePart.FeedData(sourceImagePart.GetStream());

        // Retrieve the new ID from the target image part,
        string id = targetSlidePart.GetIdOfPart(targetImagePart);

        // and assign it to the picture.
        blip.Embed.Value = id;

        // Get the shape tree that we're adding the clone to and append to it.
        ShapeTree shapeTree = targetSlide.CommonSlideData.ShapeTree;
        shapeTree.Append(elementClone);
    }

这段代码工作正常。对于像Graphic Frames这样的其他场景，它看起来有点不同，因为每个Graphic Frames可以包含多个图片对象。

// Go thru all the Picture objects in this GraphicFrame.
foreach (var sourcePicture in element.Descendants<Picture>())
{
    string rId = sourcePicture.BlipFill.Blip.Embed.Value;
    ImagePart sourceImagePart = (ImagePart)sourceSlide.SlidePart.GetPartById(rId);
    var contentType = sourceImagePart.ContentType;

    var targetPicture = elementClone.Descendants<Picture>().First(x => x.BlipFill.Blip.Embed.Value == rId);
    var targetBlip = targetPicture.BlipFill.Blip;

    ImagePart targetImagePart = targetSlidePart.AddImagePart(contentType);
    targetImagePart.FeedData(sourceImagePart.GetStream());
    string id = targetSlidePart.GetIdOfPart(targetImagePart);
    targetBlip.Embed.Value = id;
}

现在我需要对 OLE 对象做同样的事情。

// Go thru all the embedded objects in this GraphicFrame.
foreach (var oleObject in element.Descendants<OleObject>())
{
    // Get the rId of the embedded OLE object.
    string rId = oleObject.Id;

    // Get the EmbeddedPart from the source slide.
    var embeddedOleObj = sourceSlide.SlidePart.GetPartById(rId);

    // Get the content type.
    var contentType = embeddedOleObj.ContentType;

    // Create the Target Part.  Let OpenXML assign an rId.
    var targetObjectPart = targetSlide.SlidePart.AddNewPart<EmbeddedObjectPart>(contentType, null);

    // Get the embedded OLE object data from the original object.
    var objectStream = embeddedOleObj.GetStream();

    // And give it to the ObjectPart.
    targetObjectPart.FeedData(objectStream);

    // Get the new rId and assign it to the OLE Object.
    string id = targetSlidePart.GetIdOfPart(targetObjectPart);
    oleObject.Id = id;
}

但它没有用。生成的 PowerPoint 已损坏。
我究竟做错了什么？

注意:除了 rId 之外的所有代码都有效在 OLE 对象中处理。我知道它有效，因为如果我只是通过原始 rId从源对象到目标对象部分，像这样:

var targetObjectPart = targetSlide.SlidePart
   .AddNewPart<EmbeddedObjectPart>(contentType, rId);

只要 rId，它就会正常运行目标幻灯片中尚不存在，这显然不会像我需要的那样每次都起作用。
源幻灯片和目标幻灯片来自不同的 PPTX 文件。我们使用的是 OpenXML，而不是 Office Interop。

Answer 1

由于您没有提供完整的代码，因此很难判断出了什么问题。
我的猜测是您没有修改正确的对象。
在您的图片代码示例中，您正在创建和修改 elementClone .
在 ole 对象的代码示例中，您正在使用和修改 oleObject (它是 element 的后代)并且从上下文中不清楚它是源文档的一部分还是目标文档的一部分。

你可以试试这个最小的例子:

为 c:\testdata\input.pptx 使用带有一个嵌入 ole 对象的新 pptx

为 c:\testdata\output.pptx 使用新的 pptx(空白)

运行代码后，我能够在输出文档中打开嵌入的 ole 对象。

using DocumentFormat.OpenXml.Presentation;
using DocumentFormat.OpenXml.Packaging;
using System.Linq;

namespace ooxml
{
    class Program
    {
        static void Main(string[] args)
        {            
            CopyOle("c:\\testdata\\input.pptx", "c:\\testdata\\output.pptx");
        }

        private static void CopyOle(string inputFile, string outputFile)
        {
            using (PresentationDocument sourceDocument = PresentationDocument.Open(inputFile, true))
            {
                using (PresentationDocument targetDocument = PresentationDocument.Open(outputFile, true))
                {
                    var sourceSlidePart = sourceDocument.PresentationPart.SlideParts.First();
                    var targetSlidePart = targetDocument.PresentationPart.SlideParts.First();

                    
                    foreach (var element in sourceSlidePart.Slide.CommonSlideData.ShapeTree.ChildElements)
                    {
                        //clones an element, does not copy the actual relationship target (e.g. ppt\embeddings\oleObject1.bin)
                        var elementClone = element.CloneNode(true);                      
                        
                        //for each cloned OleObject, fix its relationship
                        foreach(var clonedOleObject in elementClone.Descendants<OleObject>())
                        {
                            //find the original EmbeddedObjectPart in the source document
                            //(we can use the id from the clonedOleObject to do that, since it contained the same id
                            // as the source ole object)
                            var sourceObjectPart = sourceSlidePart.GetPartById(clonedOleObject.Id);

                            //create a new EmbeddedObjectPart in the target document and copy the data from the original EmbeddedObjectPart
                            var targetObjectPart = targetSlidePart.AddEmbeddedObjectPart(sourceObjectPart.ContentType);
                            targetObjectPart.FeedData(sourceObjectPart.GetStream());

                            //update the relationship target on the clonedOleObject to point to the newly created EmbeddedObjectPath
                            clonedOleObject.Id = targetSlidePart.GetIdOfPart(targetObjectPart);
                        }

                        //add cloned element to the document
                        targetSlidePart.Slide.CommonSlideData.ShapeTree.Append(elementClone);
                    }
                    targetDocument.PresentationPart.Presentation.Save();
                }
            }
        }
    }
}

至于故障排除， OOXML Tools chrome 扩展很有帮助。
它允许比较两个文档的结构，因此更容易分析出了什么问题。
例子:

如果您只克隆所有元素，您会看到/ppt/embeddings/* 和/ppt/media/* 将丢失

或者您可以检查关系是否正确(例如，输入文档使用“rId1”来引用嵌入数据，而输出文档使用“R3a2fa0c37eaa42b5”)