Thinking out aloud - Dave Hunter's SharePoint Blog

There are many ways to upload a file using the API but finding which is the correct method takes time and effort.  You first start looking for a collection to add your SPFile to.  For example:  You can use the SPWeb.Files or Folder.Files.  The SDK use the latter

<snip>

if (oWebsite.GetFolder("Shared Documents").Exists) 
{ 
  SPFolder oFolder = oWebsite.GetFolder("Shared Documents"); 
  oFolder.Files.Add(strFilename, binFile, true); 
}

</snip>

from http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spfile.aspx

But how do you set meta data for the SPFile.  If you google this you will find people using a hashtable and passing into the SPFileCollection.Add() method.  This sounds like a feasible method, the code looks something like:

// add the metadata to File
Hashtable metaData 

metaData.Add("Title", "My Title"); 

// put on your destination file
SPFileCollection destFiles = web.GetFolder([Folder]).Files; 

destFiles.Add(Path.GetFileName(inputFile.PostedFile.FileName), inputFile.PostedFile.InputStream, metaData, true);

You would expect this to set the title field for the document.  This isn't the case.  The title field is actually called vti_Title if you look at the underlying names for the SPFile.Properties collection.  I wrote a simple app to check the values of an existing document in a SharePoint library.  The output was:

vti_canmaybeedit : true
_Author : Administrator
vti_timecreated : 08/12/2008 12:33:41
_Category :
_Status :
vti_timelastmodified : 08/12/2008 12:33:41
ContentType : Document
vti_title :
vti_replid : rid:{CE94E052-257E-4B95-946B-3B2B91CC0957}
vti_parserversion : 12.0.0.6219
PublishingStartDate :
vti_level : 1
vti_rtag : rt:CE94E052-257E-4B95-946B-3B2B91CC0957@00000000001
vti_sourcecontrolcookie : fp_internal
ContentTypeId : 0x0101003087515E5634704F98FD43AEB256E309
vti_docstoreversion : 1
vti_filesize : 17107
vti_sourcecontrolversion : V1.0
vti_docstoretype : 0
vti_author : DOMAIN\administrator
vti_modifiedby : DOMAIN\administrator
PublishingExpirationDate :

Because of the inconsistent naming I searched for a different approach.  The SPFile has a property called "Item" which contains the SPListItem which is linked to the SPFile.  You can update a SPListItem so how about if I add the file and then update the list item.  Here's the code:

// add the file   
SPFile file = docLib.RootFolder.Files.Add(newFileName, upload.PostedFile.InputStream);   

// get the list item for that file   
SPListItem item = file.Item;   

item["Title"] = "My Title";
item["Another Column"] = "My Value"; 

item.Update();

Hope this helps

By the way: VTI is an acronym of Vermeer Technologies Incorporated, which is the company Microsoft acquired in 1996.