static private PdfTypeArray ConvertContentsToArray(PdfTypeBase contents, PdfIndirectList list, PdfTypeDictionary pageDict)
{
//check the original content whether it's an array
if (contents is PdfTypeArray)
{
return(contents as PdfTypeArray); //if contents is a array just return it
}
else if (contents is PdfTypeIndirect)
{
if ((contents as PdfTypeIndirect).Direct is PdfTypeArray)
{
return((contents as PdfTypeIndirect).Direct as PdfTypeArray); //if contents is a reference to array then return that array
}
else if ((contents as PdfTypeIndirect).Direct is PdfTypeStream)
{
//if contents is a reference to a stream then create a new array and insert stream as a first element of array
var array = PdfTypeArray.Create();
array.AddIndirect(list, (contents as PdfTypeIndirect).Direct);
//Add array into list of indirect objects
list.Add(array);
//And set it as a contents of the page
pageDict.SetIndirectAt("Contents", list, array);
return(array);
}
else
{
throw new Exception("Unexcpected content type");
}
}
else
{
throw new Exception("Unexcpected content type");
}
}
static private void InsertIntoDictionary(PdfDocument doc, PdfPage page, PdfImageObject image)
{
//Get page dictionary, list of indirect objects and original page content
var pageDict = page.Dictionary;
var list = PdfIndirectList.FromPdfDocument(doc);
//Convert contents to array.
PdfTypeArray array = ConvertContentsToArray(pageDict["Contents"], list, pageDict);
//Get stream of image.
IntPtr streamHandle = Pdfium.FPDFImageObj_GenerateStream(image.Handle, page.Handle);
var stream = PdfTypeStream.Create(streamHandle);
//Add image's stream into list of indirect objects and then add it to array.
int num = list.Add(stream);
array.AddIndirect(list, num);
}
