public struct SheetInfo

{

    public string SheetName;

    public string SheetType;

    public SheetInfo(string SheetName, string SheetType)

    {

        this.SheetName = SheetName;

        this.SheetType = SheetType;

    }

}

public List<SheetInfo> XLGetSheetInfo(string fileName)

{

    //  Return a generic list containing info about all the sheets.        

    const string documentRelationshipType = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument";

    //  Fill this collection with a list of all the sheets

    List<SheetInfo> sheets = new List<SheetInfo>();

    using (Package xlPackage = Package.Open(fileName, FileMode.Open, FileAccess.Read))

    {

        //  Get the main document part (workbook.xml).

        foreach (System.IO.Packaging.PackageRelationship relationship in xlPackage.GetRelationshipsByType(documentRelationshipType))

        {

            //  There should only be one document part in the package. 

            Uri documentUri = PackUriHelper.ResolvePartUri(new Uri("/", UriKind.Relative), relationship.TargetUri);

            PackagePart documentPart = xlPackage.GetPart(documentUri);

            //  Load the contents of the workbook, which is all you 

            //  need to retrieve the names and types of the sheets:

            XmlDocument doc = new XmlDocument();

            doc.Load(documentPart.GetStream());

            //  Create a NamespaceManager to handle the default namespace, 

            //  and create a prefix for the default namespace:

            XmlNamespaceManager nsManager = new XmlNamespaceManager(doc.NameTable);

            nsManager.AddNamespace("default", doc.DocumentElement.NamespaceURI);

            //  Loop through all the nodes, retrieving the information

            //  about each sheet:

            foreach (System.Xml.XmlNode node in doc.SelectNodes("//default:sheets/default:sheet", nsManager))

            {

                string sheetName = string.Empty;

                string sheetType = "worksheet";

                sheetName = node.Attributes["name"].Value;

                XmlAttribute typeAttr = node.Attributes["type"];

                if (typeAttr != null)

                {

                    sheetType = typeAttr.Value;

                }

                sheets.Add(new SheetInfo(sheetName, sheetType));

            }

            //  There's only one document part.

            break;

        }

    }

    return sheets;

}