angular调用WCF服务，读取文件夹下图片显示列表，下载另存为图片

public string ReadImagesPaths() 
        {
            string result = string.Empty;
            try 
            {
                string path = System.IO.Directory.GetCurrentDirectory();
                DirectoryInfo files = new DirectoryInfo(path+@"\Images");
                FileInfo[] fileinfo = files.GetFiles();
                foreach (FileInfo file in fileinfo)
                {
                    //result += files +@"\"+ file.Name + ";";
                    result += file.Name + ";";
                }
            }
            catch(Exception ex)
            {
                _log.Error(ex);
            }
            return result;
        }

public Stream DownloadImage(string name)
        {
            string path = System.IO.Directory.GetCurrentDirectory();
            DirectoryInfo files = new DirectoryInfo(path + @"\Images");
            FileInfo[] fileinfo = files.GetFiles();
            FileStream filecontent;
            Byte[] filebyte = new Byte[1];
            foreach (FileInfo file in fileinfo)
            {
                if (file.Name == name)
                {
                    string filepath = files + @"\" + name;
                    filecontent = new FileStream(filepath,FileMode.Open);
                    filebyte = new Byte[filecontent.Length];
                    filecontent.Read(filebyte, 0, filebyte.Length);
                    filecontent.Close();
                }
            }
            string encodedFileName = HttpUtility.UrlEncode(name);
            
            WebOperationContext.Current.OutgoingResponse.ContentType = "application/octet-stream";
            WebOperationContext.Current.OutgoingResponse.Headers.Add("Content-Disposition", string.Format("attachment;filename=\"{0}\";filename*=utf-8‘‘ {1}", encodedFileName, encodedFileName));

            return new MemoryStream(filebyte);

<button ng-click="imageDownload(item)">下载</button>
this.downloadAccessory=function(fileId){
            location.href=hostAddress+‘MapScheme/ImageDownload?name=‘+name;
        };