批量下載文件（下載壓縮包）

首先引入ICSharpCode.SharpZipLib插件，下圖中的兩個都可以，只是版本不同（如果你有安裝過npoi，可能裏面默認會有第二個版本的插件，直接引用就好了），下面話不多說，上代碼

 

using ICSharpCode.SharpZipLib.Zip;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Web.Http;
using System.Web.Mvc;

namespace WebApplication2.Controllers
{
    public class ZipController : Controller
    {
        public void DownZip()
        {
          byte[] fileBytes=  DownAllProductClause(new List<FileHelpInfo>());
            Response.ContentType = "application/octet-stream";
            Response.AppendHeader("Content-Disposition", "attachment;filename=" + "附件" + ".rar");
            Response.AddHeader("Content-Length", fileBytes.Length.ToString());
            Response.BinaryWrite(fileBytes);
            Response.End();
            Response.Close();
        }

        public byte[] DownAllProductClause(List<FileHelpInfo> urlArray)
        {
            //安全協議設置 一般情況下如果不是訪問https則不需要設置
            ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072 | SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls;

            System.Net.WebClient myWebClient = new System.Net.WebClient();

            Dictionary<string, Stream> dc = new Dictionary<string, Stream>();

            foreach (var item in urlArray)
            {
                byte[] data = myWebClient.DownloadData(item.FilePath);
                Stream stream = new MemoryStream(data);
                dc.Add(item.FileName, stream);
            }
            byte[] fileBytes = ConvertZipStream(dc);

            return fileBytes;
        }


        public byte[] ConvertZipStream(Dictionary<string, Stream> streams)
        {
            byte[] buffer = new byte[6500];
            MemoryStream returnStream = new MemoryStream();
            var zipMs = new MemoryStream();
            /*
             * 解決中文亂碼問題
             * 
             *  ICSharpCode.SharpZipLib 0.86版本使用ZipConstants.DefaultCodePage
             *  ZipConstants.DefaultCodePage = Encoding.GetEncoding("gbk").CodePage;
             *  
             *  ICSharpCode.SharpZipLib 較新的版本使用ZipStrings.CodePage  我用的是1.2幾的版本
             *  ZipStrings.CodePage = Encoding.GetEncoding("gbk").CodePage;
             *  
             * */

            ZipStrings.CodePage = Encoding.GetEncoding("gbk").CodePage;
            using (ZipOutputStream zipStream = new ZipOutputStream(zipMs))
            {
                zipStream.SetLevel(9);
                foreach (var kv in streams)
                {
                    string fileName = kv.Key;
                    using (var streamInput = kv.Value)
                    {
                        zipStream.PutNextEntry(new ZipEntry(fileName));//fileName 如果不需要文件夾就寫文件名稱，如需多級目錄:文件夾/文件名稱
                        while (true)
                        {
                            var readCount = streamInput.Read(buffer, 0, buffer.Length);
                            if (readCount > 0)
                            {
                                zipStream.Write(buffer, 0, readCount);
                            }
                            else
                            {
                                break;
                            }
                        }

                        zipStream.Flush();
                    }
                    kv.Value.Close();
                }
                zipStream.Finish();
                zipMs.Position = 0;
                zipMs.CopyTo(returnStream, 5600);
            }
            returnStream.Position = 0;

            byte[] returnBytes = new byte[returnStream.Length];
            returnStream.Read(returnBytes, 0, returnBytes.Length);
            returnStream.Seek(0, SeekOrigin.Begin);

            return returnBytes;
        }

    }
    public class FileHelpInfo
    {
        public string FilePath { get; set; }
        public string FileName { get; set; }
    }
}