如何使用 MS Open XML SDK 从 .pptx 文件检索图像？

Question

我开始尝试Open XML SDK 2.0 for Microsoft Office。

我目前可以执行某些操作，例如检索每张幻灯片中的所有文本并获取演示文稿的大小。例如，我以这种方式执行后者：

using (var doc = PresentationDocument.Open(pptx_filename, false)) {
     var presentation = doc.PresentationPart.Presentation;

     Debug.Print("width: " + (presentation.SlideSize.Cx / 9525.0).ToString());
     Debug.Print("height: " + (presentation.SlideSize.Cy / 9525.0).ToString());
}

现在我想检索给定幻灯片中的嵌入图像。有谁知道如何做到这一点或者可以向我指出一些有关该主题的文档？

Answer 1

首先，您需要获取要从中获取图像的 SlidePart：

public static SlidePart GetSlidePart(PresentationDocument presentationDocument, int slideIndex)
{
    if (presentationDocument == null)
    {
        throw new ArgumentNullException("presentationDocument", "GetSlidePart Method: parameter presentationDocument is null");
    }

    // Get the number of slides in the presentation
    int slidesCount = CountSlides(presentationDocument);

    if (slideIndex < 0 || slideIndex >= slidesCount)
    {
        throw new ArgumentOutOfRangeException("slideIndex", "GetSlidePart Method: parameter slideIndex is out of range");
    }

    PresentationPart presentationPart = presentationDocument.PresentationPart;

    // Verify that the presentation part and presentation exist.
    if (presentationPart != null && presentationPart.Presentation != null)
    {
        Presentation presentation = presentationPart.Presentation;

        if (presentation.SlideIdList != null)
        {
            // Get the collection of slide IDs from the slide ID list.
            var slideIds = presentation.SlideIdList.ChildElements;

            if (slideIndex < slideIds.Count)
            {
               // Get the relationship ID of the slide.
               string slidePartRelationshipId = (slideIds[slideIndex] as SlideId).RelationshipId;

                // Get the specified slide part from the relationship ID.
                SlidePart slidePart = (SlidePart)presentationPart.GetPartById(slidePartRelationshipId);

                 return slidePart;
             }
         }
     }

     // No slide found
     return null;
}

然后您需要搜索 Picture 对象，该对象将包含您要查找的图像关于图像的文件名：

Picture imageToRemove = slidePart.Slide.Descendants<Picture>().SingleOrDefault(picture => picture.NonVisualPictureProperties.OuterXml.Contains(imageFileName));

Answer 2

从 Openxml 格式获取图像的最简单方法：

使用任何 zip 存档库从 pptx 文件的媒体文件夹中提取图像。这将包含文档中的图像。同样，您可以手动将扩展名 .pptx 替换为 .zip 并解压以从媒体文件夹中获取图像。

希望这有帮助。