Updating 'Created By' field in SP2010 programatically

Question

I'm trying to import data from an .xml file to a custom list in SP2010(created programmatically).

I'm able to create and update all fields except 'Created By' as it says that "Cannot update read only field".

Is there any way that I can update the "Created By" field? Only Programmatically

This is my XML code.

Note : I don't have user Id. I only have Display Name. I need field from xml code to be updated in SP.

<?xml version="1.0" encoding="iso-8859-1" ?>

<XMLExport DBName="local_Report DB">

<documentexport DOCID="DJHD7WJWA9APWPWO457C20004FE01A">

<Business>

<![CDATA[ Bank Subsidiary]]>

</Business>

<Company>

<![CDATA[ DMS Softies, India ]]>

</Company>

<Region />

<Author>

<![CDATA[ Dushyant M Sharma]]>

</Author>

</documentexport>

</XMLExport>

Answer 1

You can use the SPBuiltInFieldId.Author:

listItem[SPBuiltInFieldId.Author] = new SPFieldUserValue(web, userId, userName);
listItem.SystemUpdate(false);

Answer 2

you can also do:

SPFieldUserValue user = new SPFieldUserValue(Web, Web.CurrentUser.ID, Web.CurrentUser.LoginName);   

listItem["Author"] = user;
listItem["Editor"] = user;

listItem.Update(); 

web.Update();

SPFieldUserValue can be hard coded or as iv done getting the current user, web is the SPWeb object and listItem is the SPListItem object