Class DigitalSignatureCollection

public class DigitalSignatureCollection : IEnumerable

//workbook from a signed source file
Workbook signedWorkbook = new Workbook(@"signedFile.xlsx");
//wb.IsDigitallySigned is true when the workbook is signed already.
Console.WriteLine(signedWorkbook.IsDigitallySigned);
//get digitalSignature collection from workbook
DigitalSignatureCollection existingDsc = signedWorkbook.GetDigitalSignature();
foreach (DigitalSignature existingDs in existingDsc)
{
    Console.WriteLine(existingDs.Comments);
    Console.WriteLine(existingDs.SignTime);
    Console.WriteLine(existingDs.IsValid);
}

'workbook from a signed source file
Dim signedWorkbook As Workbook = New Workbook("newfile.xlsx")
'Workbook.IsDigitallySigned is true when the workbook is signed already.
Console.WriteLine(signedWorkbook.IsDigitallySigned)
'get digitalSignature collection from workbook
Dim existingDsc As DigitalSignatureCollection = signedWorkbook.GetDigitalSignature()
Dim existingDs As DigitalSignature
For Each existingDs In existingDsc
    Console.WriteLine(existingDs.Comments)
    Console.WriteLine(existingDs.SignTime)
    Console.WriteLine(existingDs.IsValid)
Next

public DigitalSignatureCollection()

public void Add(DigitalSignature digitalSignature)

public IEnumerator GetEnumerator()