File name having spaces it's changed to %20 in zip operation

I have use the below code for Zip file operation. It's break in file name having spaces it's converted into %20 for file name.

string destFilename = ".\\" + Path.GetFileName(fileToAdd);
Uri tempUri = new Uri("/"+Path.GetFileName(fileToAdd), UriKind.Relative);
            Uri uri = PackUriHelper.CreatePartUri(tempUri);
            if (zip.PartExists(uri))
                zip.DeletePart(uri);
            PackagePart pkgPart = zip.CreatePart(uri, System.Net.Mime.MediaTypeNames.Application.Zip, CompressionOption.Normal);
            Byte[] bites = System.IO.File.ReadAllBytes(fileToAdd);
            pkgPart.GetStream().Write(bites, 0, bites.Length);
            zip.Close();