Tìm kiếm chữ ký Qrcode trong tệp Pps

        
// Set up input Pps file
string filePath = "input.pps";

// Instantiate Signature for input file
using (GroupDocs.Signature.Signature signature = new GroupDocs.Signature.Signature(filePath))
{
        //Create search options
        QrCodeSearchOptions options = new QrCodeSearchOptions()
        {
            // specify special pages to search on 
            AllPages = false,
            // single page number
            PageNumber = 1,
            // set up text match type
            MatchType = TextMatchType.Contains,
            // specify text pattern to search
            Text = "Text signature",
            // return  Qrcode images for processing
            ReturnContent = true,
            // set up type of returned  Qrcode images
            ReturnContentType = FileType.PNG
        };

        // search for Qrcode signatures in Pps document
        List<QrCodeSignature> signatures = signature.Search<QrCodeSignature>(options);

        // process signatures which were found                
        foreach (QrCodeSignature item in signatures)
        {
            //...
        }
}