c# 把网络图片http://....png 打包成zip文件

思路：

1、把网络图片下载到服务器本地。

2、读取服务器图片的文件流

3、使用zip帮助类，把图片文件流写进zip文件流。

4、如果是文件服务器，把zip文件流 推送文件服务器，生成zip的下载url

5、如果我mvc 可以把zip的文件流返回到前端，进行格式的转换。

业务代码：

public async Task<FileStreamResult> DownloadScreenshotsZipStream()
        {
            List<ScreenshotsModel> models = new List<ScreenshotsModel>()
            {
                new ScreenshotsModel(){ ScreenshotsUrl="https://...jpg",Lablel="1号"},
                new ScreenshotsModel(){ ScreenshotsUrl="https://...jpg",Lablel="2号"},
                new ScreenshotsModel(){ ScreenshotsUrl="https://....jpg",Lablel="3号"},
                new ScreenshotsModel(){ ScreenshotsUrl="https://....jpg",Lablel="4号"}
            };
            var randomParh = Guid.NewGuid().ToString();
            var randomParhZipFileUrl = Guid.NewGuid().ToString();
            string savePath = $@"D:\ScreenshotsUrl\{randomParh}\";
            //文件创建
            if (!Directory.Exists(savePath))
            {
                Directory.CreateDirectory(savePath);
            }
            WebClient mywebclient = new WebClient();
            foreach (var item in models)
            {
                //下载文件
                mywebclient.DownloadFile(item.ScreenshotsUrl, savePath + models.IndexOf(item).ToString() + @".png");
            }
            //指定打包的文件夹路径
            string src = $@"D:\ScreenshotsUrl\{randomParh}";
            //打包之后，zip存到哪个路径
            string zipFileUrl = $@"D:\ScreenshotsUrl\{randomParhZipFileUrl}\NormalScreenshot.zip";
            if (!Directory.Exists(Path.GetDirectoryName(zipFileUrl)))
            {
                Directory.CreateDirectory(Path.GetDirectoryName(zipFileUrl));
            }
            ZipHelper zipHelper = new ZipHelper();
            bool flag = zipHelper.Zip(src, zipFileUrl);

            var memoryStream = new MemoryStream();
            using (var stream = new FileStream(zipFileUrl, FileMode.Open))
            {
                stream.CopyToAsync(memoryStream);
            }
            memoryStream.Seek(0, SeekOrigin.Begin);
            if (Directory.Exists(savePath))
            {
                //删除下载的截图和zip文件
                Directory.Delete(savePath, true);
            }
            if (Directory.Exists(Path.GetDirectoryName(zipFileUrl)))
            {
                //删除下载的截图和zip文件
                Directory.Delete(Path.GetDirectoryName(zipFileUrl), true);
            }
            return new FileStreamResult(memoryStream, "application/octet-stream");//文件流方式，指定文件流对应的ContenType。
            //return new FileStreamResult(memoryStream, "application/zip");//文件流方式，指定文件流对应的ContenType。
        }

public async Task<MessageModel<string>> DownloadScreenshotsZipOSS()
        {
            List<ScreenshotsModel> models = new List<ScreenshotsModel>()
            {
                new ScreenshotsModel(){ ScreenshotsUrl="https://..jpg",Lablel="1号"},
                new ScreenshotsModel(){ ScreenshotsUrl="https://..jpg",Lablel="2号"},
                new ScreenshotsModel(){ ScreenshotsUrl="https://..jpg",Lablel="3号"},
                new ScreenshotsModel(){ ScreenshotsUrl="https://..jpg",Lablel="4号"}
            };
            var randomParh = Guid.NewGuid().ToString();
            var randomParhZipFileUrl = Guid.NewGuid().ToString();
            string savePath = $@"D:\ScreenshotsUrl\{randomParh}\";
            //文件创建
            if (!Directory.Exists(savePath))
            {
                Directory.CreateDirectory(savePath);
            }
            WebClient mywebclient = new WebClient();
            foreach (var item in models)
            {
                //下载文件
                mywebclient.DownloadFile(item.ScreenshotsUrl, savePath + models.IndexOf(item).ToString() + @".png");
            }
            //指定打包的文件夹路径
            string src = $@"D:\ScreenshotsUrl\{randomParh}";
            //打包之后，zip存到哪个路径
            string zipFileUrl = $@"D:\ScreenshotsUrl\{randomParhZipFileUrl}\NormalScreenshot.zip";
            if (!Directory.Exists(Path.GetDirectoryName(zipFileUrl)))
            {
                Directory.CreateDirectory(Path.GetDirectoryName(zipFileUrl));
            }
            ZipHelper zipHelper = new ZipHelper();
            bool flag = zipHelper.Zip(src, zipFileUrl);

            Stream stream = GetStream.FromFilePath(zipFileUrl);
            var ossurl = OssUploadHelper.SaveContent(stream, "zip");
            stream.Dispose();
            stream.Close();
            if (Directory.Exists(savePath))
            {
                //删除下载的截图和zip文件
                Directory.Delete(savePath, true);
            }
            if (Directory.Exists(Path.GetDirectoryName(zipFileUrl)))
            {
                //删除下载的截图和zip文件
                Directory.Delete(Path.GetDirectoryName(zipFileUrl), true);
            }
            return MessageModel<string>.Success(ossurl);
        }

public class ScreenshotsModel
    {
        public string ScreenshotsUrl { get; set; }
        public string Lablel { get; set; }
    }

zip帮助类：

/// <summary>
    /// 压缩解压Zip的工具类
    /// </summary>
    public class ZipHelper
    {

        #region 扩展类

        private string rootPath = string.Empty;

        #region 压缩  

        /// <summary>   
        /// 递归压缩文件夹的内部方法   
        /// </summary>   
        /// <param name="folderToZip">要压缩的文件夹路径</param>   
        /// <param name="zipStream">压缩输出流</param>   
        /// <param name="parentFolderName">此文件夹的上级文件夹</param>   
        /// <returns></returns>   
        private bool ZipDirectory(string folderToZip, ZipOutputStream zipStream, string parentFolderName)
        {
            bool result = true;
            string[] folders, files;
            ZipEntry ent = null;
            FileStream fs = null;
            Crc32 crc = new Crc32();

            try
            {
                string entName = folderToZip.Replace(this.rootPath, string.Empty) + "/";
                //Path.Combine(parentFolderName, Path.GetFileName(folderToZip) + "/")
                ent = new ZipEntry(entName);
                zipStream.PutNextEntry(ent);
                zipStream.Flush();

                files = Directory.GetFiles(folderToZip);
                foreach (string file in files)
                {
                    fs = File.OpenRead(file);
                    byte[] buffer = new byte[fs.Length];
                    fs.Read(buffer, 0, buffer.Length);
                    ent = new ZipEntry(entName + Path.GetFileName(file));
                    ent.DateTime = DateTime.Now;
                    ent.Size = fs.Length;

                    fs.Close();

                    crc.Reset();
                    crc.Update(buffer);

                    ent.Crc = crc.Value;
                    zipStream.PutNextEntry(ent);
                    zipStream.Write(buffer, 0, buffer.Length);
                }

            }
            catch
            {
                result = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
                if (ent != null)
                {
                    ent = null;
                }
                GC.Collect();
                GC.Collect(1);
            }

            folders = Directory.GetDirectories(folderToZip);
            foreach (string folder in folders)
                if (!ZipDirectory(folder, zipStream, folderToZip))
                    return false;

            return result;
        }

        /// <summary>   
        /// 压缩文件夹    
        /// </summary>   
        /// <param name="folderToZip">要压缩的文件夹路径</param>   
        /// <param name="zipedFile">压缩文件完整路径</param>   
        /// <param name="password">密码</param>   
        /// <returns>是否压缩成功</returns>   
        public bool ZipDirectory(string folderToZip, string zipedFile, string password)
        {
            bool result = false;
            if (!Directory.Exists(folderToZip))
                return result;

            ZipOutputStream zipStream = new ZipOutputStream(File.Create(zipedFile));
            zipStream.SetLevel(6);
            if (!string.IsNullOrEmpty(password)) zipStream.Password = password;

            result = ZipDirectory(folderToZip, zipStream, "");

            zipStream.Finish();
            zipStream.Close();

            return result;
        }

        /// <summary>   
        /// 压缩文件夹   
        /// </summary>   
        /// <param name="folderToZip">要压缩的文件夹路径</param>   
        /// <param name="zipedFile">压缩文件完整路径</param>   
        /// <returns>是否压缩成功</returns>   
        public bool ZipDirectory(string folderToZip, string zipedFile)
        {
            bool result = ZipDirectory(folderToZip, zipedFile, null);
            return result;
        }

        /// <summary>   
        /// 压缩文件   
        /// </summary>   
        /// <param name="fileToZip">要压缩的文件全名</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <param name="password">密码</param>   
        /// <returns>压缩结果</returns>   
        public bool ZipFile(string fileToZip, string zipedFile, string password)
        {
            bool result = true;
            ZipOutputStream zipStream = null;
            FileStream fs = null;
            ZipEntry ent = null;

            if (!File.Exists(fileToZip))
                return false;

            try
            {
                fs = File.OpenRead(fileToZip);
                byte[] buffer = new byte[fs.Length];
                fs.Read(buffer, 0, buffer.Length);
                fs.Close();

                fs = File.Create(zipedFile);
                zipStream = new ZipOutputStream(fs);
                if (!string.IsNullOrEmpty(password)) zipStream.Password = password;
                ent = new ZipEntry(Path.GetFileName(fileToZip));
                zipStream.PutNextEntry(ent);
                zipStream.SetLevel(6);

                zipStream.Write(buffer, 0, buffer.Length);

            }
            catch
            {
                result = false;
            }
            finally
            {
                if (zipStream != null)
                {
                    zipStream.Finish();
                    zipStream.Close();
                }
                if (ent != null)
                {
                    ent = null;
                }
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
            }
            GC.Collect();
            GC.Collect(1);

            return result;
        }

        /// <summary>   
        /// 压缩文件   
        /// </summary>   
        /// <param name="fileToZip">要压缩的文件全名</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <returns>压缩结果</returns>   
        public bool ZipFile(string fileToZip, string zipedFile)
        {
            bool result = ZipFile(fileToZip, zipedFile, null);
            return result;
        }

        /// <summary>   
        /// 压缩文件或文件夹   
        /// </summary>   
        /// <param name="fileToZip">要压缩的路径</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <param name="password">密码</param>   
        /// <returns>压缩结果</returns>   
        public bool Zip(string fileToZip, string zipedFile, string password)
        {
            bool result = false;
            if (Directory.Exists(fileToZip))
            {
                this.rootPath = Path.GetDirectoryName(fileToZip);
                result = ZipDirectory(fileToZip, zipedFile, password);
            }
            else if (File.Exists(fileToZip))
            {
                this.rootPath = Path.GetDirectoryName(fileToZip);
                result = ZipFile(fileToZip, zipedFile, password);
            }
            return result;
        }

        /// <summary>   
        /// 压缩文件或文件夹   
        /// </summary>   
        /// <param name="fileToZip">要压缩的路径</param>   
        /// <param name="zipedFile">压缩后的文件名</param>   
        /// <returns>压缩结果</returns>   
        public bool Zip(string fileToZip, string zipedFile)
        {
            bool result = Zip(fileToZip, zipedFile, null);
            return result;

        }

        #endregion

        #region 解压  

        /// <summary>   
        /// 解压功能(解压压缩文件到指定目录)   
        /// </summary>   
        /// <param name="fileToUnZip">待解压的文件</param>   
        /// <param name="zipedFolder">指定解压目标目录</param>   
        /// <param name="password">密码</param>   
        /// <returns>解压结果</returns>   
        public bool UnZip(string fileToUnZip, string zipedFolder, string password)
        {
            bool result = true;
            FileStream fs = null;
            ZipInputStream zipStream = null;
            ZipEntry ent = null;
            string fileName;

            if (!File.Exists(fileToUnZip))
                return false;

            if (!Directory.Exists(zipedFolder))
                Directory.CreateDirectory(zipedFolder);

            try
            {
                zipStream = new ZipInputStream(File.OpenRead(fileToUnZip));
                if (!string.IsNullOrEmpty(password)) zipStream.Password = password;
                while ((ent = zipStream.GetNextEntry()) != null)
                {
                    if (!string.IsNullOrEmpty(ent.Name))
                    {
                        fileName = Path.Combine(zipedFolder, ent.Name);
                        fileName = fileName.Replace('/', '\\');//change by Mr.HopeGi   

                        if (fileName.EndsWith("\\"))
                        {
                            Directory.CreateDirectory(fileName);
                            continue;
                        }

                        fs = File.Create(fileName);
                        int size = 2048;
                        byte[] data = new byte[size];
                        while (true)
                        {
                            size = zipStream.Read(data, 0, data.Length);
                            if (size > 0)
                                fs.Write(data, 0, data.Length);
                            else
                                break;
                        }
                    }
                }
            }
            catch
            {
                result = false;
            }
            finally
            {
                if (fs != null)
                {
                    fs.Close();
                    fs.Dispose();
                }
                if (zipStream != null)
                {
                    zipStream.Close();
                    zipStream.Dispose();
                }
                if (ent != null)
                {
                    ent = null;
                }
                GC.Collect();
                GC.Collect(1);
            }
            return result;
        }

        /// <summary>   
        /// 解压功能(解压压缩文件到指定目录)   
        /// </summary>   
        /// <param name="fileToUnZip">待解压的文件</param>   
        /// <param name="zipedFolder">指定解压目标目录</param>   
        /// <returns>解压结果</returns>   
        public bool UnZip(string fileToUnZip, string zipedFolder)
        {
            bool result = UnZip(fileToUnZip, zipedFolder, null);
            return result;
        }

        #endregion

        #endregion


        /// <summary>
        /// 解压缩一个zip文件
        /// </summary>
        /// <param name="inputStream">要解压的zip文件</param>
        /// <param name="password">zip文件的密码</param>
        public static IList<KeyValue<Stream>> UnZipStream(Stream inputStream, string password = "")
        {
            inputStream.Position = 0;

            IList<KeyValue<Stream>> result = new List<KeyValue<Stream>>();

            ZipInputStream zipStream = new ZipInputStream(inputStream);
            if (password != "")
            {
                zipStream.Password = password;
            }

            try
            {
                ZipEntry theEntry;
                while ((theEntry = zipStream.GetNextEntry()) != null)
                {
                    MemoryStream memoryStream = new MemoryStream();
                    int size = 2048;
                    byte[] data = new byte[2048];
                    while (true)
                    {
                        size = zipStream.Read(data, 0, data.Length);
                        if (size > 0)
                            memoryStream.Write(data, 0, size);
                        else
                            break;
                    }
                    memoryStream.Position = 0;
                    result.Add(new KeyValue<Stream>
                    {
                        Key = theEntry.Name,
                        Value = memoryStream
                    });
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            finally
            {
                zipStream.Close();
            }

            //返回自然排序的文件列表
            return result.OrderBy(a => a.Key.Split('.')[0], new StringCompare()).ToList();
        }

        /// <summary>
        /// 解压缩文件到指定目录
        /// </summary>
        /// <param name="zipPath"></param>
        /// <param name="unZipFolder"></param>
        /// <returns></returns>
        public static void UnZipFromPathToFolder(string zipPath, string unZipFolder)
        {
            //解压缩文件到指定目录
            new UnZipDir(zipPath, unZipFolder);
        }

        /// <summary>
        /// 解压二进制ZIP文件到二进制文件数组
        /// </summary>
        /// <param name="buffer"></param>
        /// <returns></returns>
        public static IList<ZipFileBuffer> UnZipFromBytesToBytes(byte[] buffer)
        {
            //创建工作目录
            string workFolder = Path.GetTempPath() + Guid.NewGuid().ToString().Replace("-", "").ToUpper() + "\\";
            DirectoryInfo workDirectory = Directory.CreateDirectory(workFolder);
            string zipPath = workFolder + "data.zip";
            string unZipFolder = workFolder + "data";

            //保存zip临时文件
            FileStream fileStream = new FileStream(zipPath, FileMode.Create);
            BinaryWriter binaryWriter = new BinaryWriter(fileStream);
            binaryWriter.Write(buffer);
            binaryWriter.Close();

            //解压缩zip文件到临时目录
            UnZipFromPathToFolder(zipPath, unZipFolder);

            //读取全部文件到数组
            IList<FileInfo> fileList = new List<FileInfo>();
            GetDirectoryFiles(fileList, new DirectoryInfo(unZipFolder));

            //读取全部文件到输出返回
            IList<ZipFileBuffer> result = new List<ZipFileBuffer>();

            foreach (FileInfo file in fileList)
            {
                result.Add(new ZipFileBuffer
                {
                    RelativePath = file.FullName.Replace(unZipFolder + "\\", "").Replace("\\", "/"),
                    FileBuffer = File.ReadAllBytes(file.FullName)
                });
            }

            //删除工作目录
            workDirectory.Delete(true);

            return result;
        }

        /// <summary>
        /// 解压二进制ZIP文件到指定目录
        /// </summary>
        /// <param name="buffer"></param>
        /// <param name="unZipFolder"></param>
        public static void UnZipFromBytesToFolder(byte[] buffer, string unZipFolder)
        {
            //创建工作目录
            string workFolder = Path.GetTempPath() + Guid.NewGuid().ToString().Replace("-", "").ToUpper() + "\\";
            DirectoryInfo workDirectory = Directory.CreateDirectory(workFolder);
            string zipPath = workFolder + "data.zip";

            //保存zip临时文件
            FileStream fileStream = new FileStream(zipPath, FileMode.Create);
            BinaryWriter binaryWriter = new BinaryWriter(fileStream);
            binaryWriter.Write(buffer);
            binaryWriter.Close();

            //解压缩zip文件到指定目录
            UnZipFromPathToFolder(zipPath, unZipFolder);

            //删除工作目录
            workDirectory.Delete(true);
        }


        #region 私有方法

        /// <summary>
        /// 遍历文件夹中的所有文件
        /// </summary>
        /// <param name="fileList"></param>
        /// <param name="dic"></param>
        private static void GetDirectoryFiles(IList<FileInfo> fileList, DirectoryInfo dic)
        {
            foreach (FileInfo file in dic.GetFiles())
            {
                fileList.Add(file);
            }
            foreach (DirectoryInfo subdic in dic.GetDirectories())
            {
                GetDirectoryFiles(fileList, subdic);
            }
        }

        #endregion




    }