上傳檔案帶進度條

   // 儲存位元組
                        using (FileStream fs = new FileStream(Path.Combine(path, fileName), FileMode.Create))
                        {                        
                            while (uploadInfo.UploadedLength < uploadInfo.ContentLength)
                            {
                               //從輸入流放進緩衝區
                                int bytes = this.fileUpload.PostedFile.InputStream.Read(buffer, 0, bufferSize);
                                // 位元組寫入檔案流
                                fs.Write(buffer, 0, bytes);
                                //  更新大小
                                uploadInfo.UploadedLength += bytes;

                                //  執行緒睡眠 上傳就更慢 這樣就可以看到進度條了
                                System.Threading.Thread.Sleep(100);
                            }
                        }