private string GetBookmarkTitle(IntPtr bookmark)
{
uint length = PdfiumLibrary.FPDFBookmark_GetTitle(bookmark, null, 0);
byte[] bytes = new byte[length];
PdfiumLibrary.FPDFBookmark_GetTitle(bookmark, bytes, length);
string title = Encoding.Unicode.GetString(bytes);
if (title.Length > 0 && title[title.Length - 1] == 0)
{
title = title.Substring(0, title.Length - 1);
}
return(title);
}