Error message:
System.InvalidCastException: 'Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.Forms.FormFieldsTree' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfArray'.'Error message:
System.InvalidCastException: 'Unable to cast object of type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Types.PdfArray' to type 'Telerik.Windows.Documents.Fixed.FormatProviders.Pdf.Model.Elements.Functions.FunctionObject'.'16 0 obj <</AP<</N<</Off null/On 188 0 R>>/D<</Off 189 0 R/On 190 0 R>>>>/AS/Off/F 4/FT/Btn/H/T/P 19 0 R/Rect[ 40.3 690.45 56.15 706.7999]/Subtype/Widget/T(Einraeumung:Grabnutzungsrechts)/Type/Annot>> endobj
When merging documents` pages using the PdfStreamWriter the Form Fields are not copied:
using (PdfStreamWriter fileWriter = new PdfStreamWriter(File.OpenWrite(document2Name)))
{
// Iterate through the files you would like to merge
for (int i = 0; i < 2; i++)
{
// Open each of the files
using (PdfFileSource fileToMerge = new PdfFileSource(File.OpenRead(document1Name)))
{
// Iterate through the pages of the current document
foreach (PdfPageSource pageToMerge in fileToMerge.Pages)
{
// Append the current page to the fileWriter, which holds the stream of the result file
fileWriter.WritePage(pageToMerge);
}
}
}
}
A possible workaround is to use the RadFixedDocument`s Merge() method:
document1.Merge(document2);