แก้ไขและอัปเดตลายเซ็น Text ที่วางไว้ที่ Pdf files

        
// Set up input Pdf file
string filePath = "input.pdf";

// Instantiate Signature for input file
using (GroupDocs.Signature.Signature signature = new GroupDocs.Signature.Signature(filePath))
{
        // Id of signature which is supposed to be updated
        // such Id might be got as a result of search operation
        string id = "ff988ab1-7403-4c8d-8db7-f2a56b9f8530";

        // provide signature features to update
        // set up particular signature id
        TextSignature signatureToUpdate = new TextSignature(id)
        {
            // specify signature width
            Width = 130,
            // specify signature height
            Height = 20,
            // set left position
            Left = 40,
            // set top position
            Top = 50,
            // set up new text
            Text = "Mr. John Smith"
        };

        // update signature
        bool updateResult = signature.Update(signatureToUpdate);

        // process updation result
        if (updateResult)
        {
            Console.WriteLine("Signature was updated successfully!");
        }
}