一，设计多图片打包下载逻辑：
1，如果是要拉取腾讯云等资源服务器的图片，
2，我们先把远程图片拉取到本地的临时文件夹，
3，然后压缩临时文件夹，
4，压缩完删除临时文件夹，
5，返回压缩完给用户，
6，用户就去请求下载接口，当下载完后，删除压缩包
二，如下代码，ImageUtil
using System; using System.Collections.Generic; using System.IO; using System.IO.Compression; using System.Linq; using System.Net; using System.Text; using System.Threading; using System.Threading.Tasks; using System.Web; namespace Common { /// <summary> /// 要引用 /// System.IO.Compression.FileSystem /// System.IO.Compression /// </summary> public static class ImageUtil { #region 图片打包下载 /// <summary> /// 下载图片到本地，压缩 /// </summary> /// <param name="urlList">图片列表</param> /// <param name="curDirName">要压缩文档的路径</param> /// <param name="curFileName">压缩后生成文档保存路径</param> /// <returns></returns> public static bool ImagePackZip(List<string> urlList, string curDirName, string curFileName) { return CommonException(() => { //1.新建文件夹 if (!Directory.Exists(curDirName)) Directory.CreateDirectory(curDirName); //2.下载文件到服务器临时目录 foreach (var url in urlList) { DownPicToLocal(url, curDirName + "\\"); Thread.Sleep(60);//加个延时，避免上一张图还没下载完就执行下一张图的下载操作 } //3.压缩文件夹 if (!File.Exists(curFileName)) ZipFile.CreateFromDirectory(curDirName, curFileName); //压缩 //异步删除压缩前，下载的临时文件 Task.Run(() => { if (Directory.Exists(curDirName)) Directory.Delete(curDirName, true); }); return true; }); } /// <summary> /// 下载压缩包 /// </summary> /// <param name="targetfile">目标临时文件地址</param> /// <param name="filename">文件名</param> public static bool DownePackZip(string targetfile, string filename) { return CommonException(() => { FileInfo fileInfo = new FileInfo(targetfile); HttpResponse rs = System.Web.HttpContext.Current.Response; rs.Clear(); rs.ClearContent(); rs.ClearHeaders(); rs.AddHeader("Content-Disposition", "attachment;filename=" + $"{filename}"); rs.AddHeader("Content-Length", fileInfo.Length.ToString()); rs.AddHeader("Content-Transfer-Encoding", "binary"); rs.AddHeader("Pragma", "public");//这两句解决https的cache缓存默认不给权限的问题 rs.AddHeader("Cache-Control", "max-age=0"); rs.ContentType = "application/octet-stream"; rs.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312"); rs.WriteFile(fileInfo.FullName); rs.Flush(); rs.End(); return true; }); } /// <summary> /// 下载一张图片到本地 /// </summary> /// <param name="url"></param> public static bool DownPicToLocal(string url, string localpath) { return CommonException(() => { string fileprefix = DateTime.Now.ToString("yyyyMMddhhmmssfff"); var filename = $"{fileprefix}.jpg"; HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.Timeout = 60000; WebResponse response = request.GetResponse(); using (Stream reader = response.GetResponseStream()) { FileStream writer = new FileStream(localpath + filename, FileMode.OpenOrCreate, FileAccess.Write); byte[] buff = new byte[512]; int c = 0; //实际读取的字节数 while ((c = reader.Read(buff, 0, buff.Length)) > 0) { writer.Write(buff, 0, c); } writer.Close(); writer.Dispose(); reader.Close(); reader.Dispose(); } response.Close(); response.Dispose(); return true; }); } /// <summary> /// 公用捕获异常 /// </summary> /// <param name="func"></param> /// <returns></returns> private static bool CommonException(Func<bool> func) { try { return func.Invoke(); } catch (Exception ex) { return false; } } #endregion } }
三，测试MVC代码
using Common; using Newtonsoft.Json; using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Threading; using System.Web.Mvc; namespace PackImageZip.Controllers { public class HomeController : Controller { private static object obj = new object(); public ActionResult Contact() { ///锁，多文件请求打包，存在并发情况 lock (obj) { var DownPicpath = System.Web.HttpContext.Current.Server.MapPath("/DownPicPackge");//服务器临时文件目录 string curFileName = DateTime.Now.ToString("yyyyMMddHHmmssfff") + ".zip"; ///多次请求文件名一样，睡眠一下 Thread.Sleep(2000); ////保存拉取服务器图片文件夹 string curDirName = $"/{DateTime.Now.ToString("yyyyMMddHHmmssfff")}/"; List<string> urlList = new List<string>(); urlList.Add("https://cdn.duitang.com/uploads/item/201409/08/20140908155026_RdUwH.thumb.700_0.jpeg"); urlList.Add("https://cdn.duitang.com/uploads/item/201409/08/20140908155026_RdUwH.thumb.700_0.jpeg"); urlList.Add("https://cdn.duitang.com/uploads/item/201409/08/20140908155026_RdUwH.thumb.700_0.jpeg"); urlList.Add("https://cdn.duitang.com/uploads/item/201409/08/20140908155026_RdUwH.thumb.700_0.jpeg"); var isOk = ImageUtil.ImagePackZip(urlList, DownPicpath + curDirName, $"{DownPicpath}/{curFileName}"); var json = JsonConvert.SerializeObject(new { isok = isOk.ToString(), curFileName = curDirName }); return Content(json); } } /// <summary> /// 下载压缩包 /// </summary> /// <param name="curFileName">文件名</param> /// <returns></returns> public ActionResult DownePackZip(string curFileName) { try { curFileName = curFileName + ".zip"; var DownPicpath = System.Web.HttpContext.Current.Server.MapPath("/DownPicPackge"); var flag = ImageUtil.DownePackZip(DownPicpath + "/" + curFileName, curFileName); ////flag返回包之后就可以删除包，因为包的已经转为流返回给客户端，无需读取源文件 if (flag && Directory.Exists(DownPicpath)) System.IO.File.Delete(DownPicpath + "/" + curFileName); return Content(flag.ToString()); } catch (Exception ex) { return Content(ex.Message); } } } }