Proper way to get the latest published Major version of Document

Question

Hi,
I have a Document Library which has "Create major and minor (draft) versions" enabled.
Now, from my C# application I need to fetch the latest major version of a document from that library.
What is the proper way to do this?
As of right now, I do the following:
return sourceFolder.Files["documentName.docx"]; // sourceFolder is a SPFolder object
Now, I don't trust that this will always give me the latest published major version of the document. Or am I wrong? If I'm wrong, how should I do this?
Thanks!

Answer 1

Problem
When you store critical documents in the SharePoint libraries, sometimes it becomes necessary to track all the changes and to maintain version history for them.
Solution
There might be a time when you would need to restore files back to an older version if any inadvertent change happens. You can also track changes for auditing purposes.
So how does SharePoint allow creating different versions of documents? How does version history work? What are the different types of versions we can maintain for our library or list and how can we revert back to an older version?
SharePoint allows you to enable (by default it's disabled) versioning on lists and libraries. Once enabled, SharePoint will maintain multiple versions of the document or list which gets incremented on each change iteration. There are three different versioning
settings:
No versioning - This is the default setting in which the current version overwrites the older version. There are no previous versions stored. This setting is not recommended especially if your document library contains critical or important
documents.
Create major versions - Also called simple versioning, in this setting the document versions will be numbered with whole numbers, called major versions, i.e. 1, 2, 3, 4 etc.
Create major and minor (or draft) versions - In this setting document versions will be numbered with whole numbers (1, 2, 3, 4 etc.) as well as numbers with decimals (.1, .2, .3, .4 etc.). The whole number is called the major version
(indicates final copy) and the numbers with a decimal are called minor versions (indicates work is still in progress). You use this setting if your document goes through several iterations/drafts/reviews (minor versions) and you want only the final copy (major
version) to be published to a broader audience.
Please note for a list or list items, the only option available for versioning is creating major versions, no minor versions are created.
Once versioning is enabled SharePoint automatically and transparently creates the next version of the document whenever a user updates a document in the library. These are some of the different scenarios when SharePoint will create a new version for your
document or list item:
When a new document or list item is created or uploaded into SharePoint, version 1 is created if the option
Create major versions option is enabled or version 0.1 is created when
Create major and minor (or draft) versions is enabled (not applicable for list items) and when you publish it then next higher major version is created.
When you upload a document with the same name as an already existing document in the library and check the
Add as a new version to existing files check box, the existing file becomes an older version and the new uploaded document will have next higher version number.
When any properties (metadata fields) of the document or list item is changed.
When you Check-in a document that was previously Checked-out.
When you open a document in the associated application, edit and save it for the first time. On subsequent changes no new versions will be created as long as you don't close the application and re-open it.
When you restore the old version of the document.
Please note, although the demonstration in this tip has been shown in SharePoint 2010, the versioning feature has been part of previous SharePoint versions as well.
Reference URL with Example :
http://www.mssharepointtips.com/tip.asp?id=1047
Thanks
Jaison A