List of fields in a list SharePoint programtically:

Below post will help you to get the list of columns that is displayed when you view the items in the list programtically:

var fields = from SPField f in list.Fields                     where !f.Hidden && f.AuthoringInfo == "" &&                                   f.Type! = SPFieldType.Attachments &&                                   f.Title! = "SharingID" &&                                   f.Type! = SPFieldType.WorkflowStatus                     orderby f.Title                     select new { ListItem = new ListItem(f.Title, f.Id.ToString()),                                 Readonly = f.ReadOnlyField, FieldType = f.Type };

 Note: we will get the null result to the “f.AuthoringInfo” in SharePoint 2007 but we can get string empty result to the “f.AuthoringInfo” in SharePoint 2010.

 So, use: f.AuthoringInfo == null [In SP2007] & f.AuthoringInfo == ""[In SP2010]

Output: We can get the list of viewable lists by default once create a sample list in SharePoint.