C#WebService下载文件

WebService项目中的Web.config配置代码

    <appSettings>
        <add key="UploadFileFolder" value="/Uploads/TestUpload/" />
    </appSettings>

WebService项目中的ImageService.asmx代码
        /// <summary>
        /// Webservice中的下载文件处理函数
        /// </summary>
        /// <param name="filePath">文件路径</param>
        /// <returns>返回文件流</returns>
        [WebMethod(Description = "下载服务器站点文件，传递文件相对路径")]
        public byte[] DownloadFile(string strFilePath)
        {
            FileStream fs = null;
            string CurrentUploadFolderPath = Server.MapPath(ConfigurationManager.AppSettings["UploadFileFolder"]);
            string CurrentUploadFilePath = CurrentUploadFolderPath + strFilePath;
            if (File.Exists(CurrentUploadFilePath))
            {
                try
                {
                    ///打开现有文件以进行读取。
                    fs = File.OpenRead(CurrentUploadFilePath);
                    int b1;
                    System.IO.MemoryStream tempStream = new System.IO.MemoryStream();
                    while ((b1 = fs.ReadByte()) != -1)
                    {
                        tempStream.WriteByte(((byte)b1));
                    }
                    return tempStream.ToArray();
                }
                catch (Exception ex)
                {
                    return new byte[0];
                }
                finally
                {
                    fs.Close();
                }
            }
            else
            {
                return new byte[0];
            }
        }

Winform项目中的窗体下载按钮代码
        private void btnDownload_Click(object sender, EventArgs e)
        {
            string CurrentServiceFilePath = this.txtServiceFile.Text.Trim();
            string CurrentDownloadFolderPath = this.txtDownloadFolder.Text.Trim();

            if (CurrentServiceFilePath == "" || CurrentDownloadFolderPath == "")
            {
                MessageBox.Show(DownloadImage(CurrentServiceFilePath, CurrentDownloadFolderPath));      
            }
            else if (CurrentServiceFilePath == "")
            {
                MessageBox.Show("请填写要下载的服务器文件路径和选择本地保存目录");
            }
            else if (CurrentDownloadFolderPath == "")
            {

                MessageBox.Show("请填写要下载的服务器文件路径和选择本地保存目录");
         
            }
        }

Winform项目中的窗体下载按钮调用函数

        /// <summary>
        /// 通过WebService下载文件
        /// </summary>
        /// <param name="ServiceFilePath">服务器图片路径</param>
        /// <param name="DownloadFolderPath">本地图片路径</param>
        private string DownloadImage(string ServiceFilePath, string DownloadFolderPath)
        {
            try
            {
                string DownloadFileName="";
                if (ServiceFilePath.Contains("/"))
                {
                    DownloadFileName=ServiceFilePath.Substring(ServiceFilePath.LastIndexOf("/"));
                }
                else
                {
                    DownloadFileName = ServiceFilePath;
                }
                string DownloadFilePath = DownloadFolderPath +"\\"+ DownloadFileName;
                localhost.ImageService myImageService=new localhost.ImageService();
                byte[] bytes = myImageService.DownloadFile(ServiceFilePath);
                if (bytes != null)
                {
                    if (!Directory.Exists(DownloadFolderPath)) {
                        Directory.CreateDirectory(DownloadFolderPath);
                    }
                    if (!File.Exists(DownloadFilePath))
                    {
                        File.Create(DownloadFilePath).Dispose();
                    }
                    //如果不存在完整的上传路径就创建
                    FileInfo downloadInfo = new FileInfo(DownloadFilePath);
                    if (downloadInfo.IsReadOnly) { downloadInfo.IsReadOnly = false; }
                    //定义并实例化一个内存流，以存放提交上来的字节数组。
                    MemoryStream ms = new MemoryStream(bytes);
                    //定义实际文件对象，保存上载的文件。
                    FileStream fs = new FileStream(DownloadFilePath, FileMode.Create);
                    ///把内内存里的数据写入物理文件
                    ms.WriteTo(fs);
                    fs.Flush();
                    ms.Flush();
                    ms.Close();
                    fs.Close();
                    fs = null;
                    ms = null;
                }
                return "下载成功";
            }
            catch(Exception ex)
            {
                return "下载失败"+ex.Message;
            }
        }