创建文件后访问文件

我有以下代码，用于在内存中创建一个 XML 文件，对其进行更新，然后将其添加到表单库中。

// Creates a new XML document in memory
XmlDocument newCRF = new XmlDocument();
// Loads an existing XML file into that in-memory document
newXMLdoc.Load("Template.xml");
// Write the XML file to a document library
using (SPSite newSite = new SPSite("http://sharepoint/newsite"))
{
    using (SPWeb newWeb = newSite.OpenWeb())
    {
        SPList newLibrary = newWeb.Lists["Test Library"];
        byte[] xmlData = System.Text.Encoding.UTF8.GetBytes(newXMLdoc.OuterXml);
        // Save file to form library
        using (MemoryStream ms = new MemoryStream(xmlData))
        {
            SPFile newFileInLibrary = newLibrary.RootFolder.Files.Add("Filename.xml", ms);
        }
    }
}

如何访问"newFileInLibrary"对象，以便可以更改其属性（例如"创建者"）？

    // Save file to form library
    SPFile newFileInLibrary = null;
    using (MemoryStream ms = new MemoryStream(xmlData))
    {
        newFileInLibrary = newLibrary.RootFolder.Files.Add("Filename.xml", ms);
    }
    SPListItem fileItem = newFileInLibrary.Item;
    DoSomethingWith(fileItem["Created"]);