PdfTestHelper.cs

public static bool PdfContains(byte[] pdfcontent, string text)
{
  using (var pdfReader = new PdfReader(pdfcontent))
  {
    for (int page = 1; page <= pdfReader.NumberOfPages; page++)
    {
      var strategy = new SimpleTextExtractionStrategy();
      string currentText = PdfTextExtractor.GetTextFromPage(
        pdfReader, page, strategy);
                
      if (currentText.Contains(text))
        return true        
    }
    return false
  }
}