Nick Grattan’s SharePoint Blog

This method “CreateDocument” will create a new document in a SharePoint document library using a content type. It will copy the document template associated with the content type into the new document:

// Creates document in given list (root folder).
// Returns true if the file was created, false if it already
// exists or throws exception for other failure
protected bool CreateDocument( string sFilename,
                string sContentType, string sList)
{
    try
    {
        SPSite site = SPContext.Current.Site;

        using (SPWeb web = site.OpenWeb())
        {
            SPList list = web.Lists[sList];
            // this always uses root folder
            SPFolder folder = web.Folders[sList];
            SPFileCollection fcol = folder.Files;

            // find the template url and open
            string sTemplate =
                list.ContentTypes[sContentType].DocumentTemplateUrl;
            SPFile spf = web.GetFile(sTemplate);
            byte[] binFile = spf.OpenBinary();
            // Url for file to be created
            string destFile = fcol.Folder.Url + “/” + sFilename;

            // create the document and get SPFile/SPItem for
            // new document
            SPFile addedFile = fcol.Add(destFile, binFile, false);
            SPItem newItem = addedFile.Item;
            newItem["ContentType"] = sContentType;
            newItem.Update();
            addedFile.Update();
            return true;
        }
    }
    catch (SPException spEx)
    {
        // file already exists?
        if (spEx.ErrorCode == -2130575257)
            return false;
        else
            throw spEx;
    }
}

This code:

1. Gets a SPSite for the current site collection, and opens an SPWeb for the site.
2. Gets a SPList for the given list, and then an SPFolder for the root folder in this list. This code always creates the document in the root folder, but the code can easily be changed to place the document in any folder in the document library.
3. Gets a SPFileCollection for the documents in the folder.
4. “DocumentTemplateUrl” is used to return the Url of document template associated with the given content type.
5. Get an SPFile for the document template in spf and open it for binary access using OpenBinary
6. Add a new document to the folder through the SPFileCollection referenced by fcol.
7. Get an SPItem for the new document and set the “ContentType” column to ensure it uses the correct content type (it will default to the first content type in the document library).
8. Update the item and the added file.
9. The catch section checks for an -2130575257 error, which indicates the file already exists.