I am getting next error when I try to build:

Does not contain definition or extension method

I have a class like this:

[Serializable]
public class JobFile
{
    private FileInfo mFileInfo;
    private string mJobNumber = string.Empty;
    private string mBaseJobNumber = string.Empty;
    private Guid mDocumentTytpeid = Guid.Empty;

    public string DocumentTypeDescription
    {
        get
        {
            string description;
            DocumentType DocType;
            DocType = DocumentType.GetDocType(DocumentTypeCode);
            if (DocType.Code == null)
                description = "Unknown";
            else
                description = DocType.Description;
            return description;
        }
    }

    public Guid DocumentTypeID
    {
        get
        {
            DocumentType DocType;
            DocType = DocumentType.GetDocType(DocumentTypeCode);
            if (DocType.Code == null)
                mDocumentTytpeid = Guid.Empty;
            else
                mDocumentTytpeid = DocType.Id;
            return mDocumentTytpeid;
        }
    }

Now i am trying to get the value of Documenttypeid in my other class like so:

foreach (FileInfo fi in files)
{
    JobFile jf = null;
    jf = new JobFile(ref fi);
    f.DocumentTypeId = jf.DocumentTypeID; //<-- error is here
}

Does anyone know what could be wrong and how to fix it? Thanks.

The error message is very clear about what's wrong. You're trying to use a property that doesn't exist, and seeing as how the error is occuring on this line:

f.DocumentTypeId = jf.DocumentTypeID;

It could only be one of two things:

1. f does not exist
2. f.DocumentTypeId does not exist.
3. jf.DocumentTypeID does not exist

Honestly, I would check to make sure that f.DocumentTypeId is not supposed to be f.DocumentTypeID. C# is picky about things like that, and a small mistake like that would cause the error that you're receiving.