C# Progress Bar Background Worker

public void CopyDirectory(string strSource, string strDestination)
        {
            string strDestinationFile = string.Empty;
            DirectoryInfo Dirinfo = new DirectoryInfo(strSource);
            if (!Directory.Exists(strDestination))
            {
                Directory.CreateDirectory(strDestination);
            }
            foreach (FileSystemInfo filesInfo in Dirinfo.GetFileSystemInfos())
            {
                strDestinationFile = Path.Combine(strDestination, filesInfo.Name);

                //Check If it's a file
                if (filesInfo is FileInfo)
                {
                    File.Copy(filesInfo.FullName, strDestinationFile, true);
                }
                else
                    // Recall The same Function
                    CopyDirectory(filesInfo.FullName, strDestinationFile);
					}
					}

public static long DirSize(DirectoryInfo d)
{
    long size = 0;
    FileInfo[] fis = d.GetFiles();
    foreach (FileInfo fi in fis)
    {
        size += fi.Length;
    }
    DirectoryInfo[] dis = d.GetDirectories();
    foreach (DirectoryInfo di in dis)
    {
        size += DirSize(di);
    }
    return size; //Returns the size of the whole directory for later usage on progress Bar