private bool CreateMediaFile()
{
    // Prepare the parameters
    string filePath = "~/CMSAPIExamples/Code/Tools/MediaLibrary/Files/Powered_by_kentico2.gif";

    // Get media library
    MediaLibraryInfo library = MediaLibraryInfoProvider.GetMediaLibraryInfo("MyNewLibrary", CMSContext.CurrentSiteName);
    if (library != null)
    {
        // Create new media file object
        MediaFileInfo mediaFile = new MediaFileInfo(Server.MapPath(filePath), library.LibraryID);

        // Create file info
        FileInfo file = FileInfo.New(Server.MapPath(filePath));
        if (file != null)
        {
            // Set the properties
            mediaFile.FileName = "MyNewFile";
            mediaFile.FileTitle = "My new file title";
            mediaFile.FileDescription = "My new file description.";
            mediaFile.FilePath = "MyNewFolder/MyNewFile.gif";
            mediaFile.FileExtension = file.Extension;
            mediaFile.FileMimeType = "image/gif";
            mediaFile.FileSiteID = CMSContext.CurrentSiteID;
            mediaFile.FileLibraryID = library.LibraryID;
            mediaFile.FileSize = file.Length;

            // Create the media file
            MediaFileInfoProvider.SetMediaFileInfo(mediaFile);

            return true;
        }
    }

    return false;
}