压缩文件

用法：

[ResponseCache(Duration = 0)]
public IActionResult DownloadFile()
{
       //NUGET 安装 SharpZipLib

        ZipSugar zc = new ZipSugar();
       string webRootPath = _webHostEnvironment.ContentRootPath+"\\A\\";//压缩文件目录

       //压缩后的Zip文件路径
        var zippath = webRootPath+ "1.zip";

         if(System.IO.File.Exists(zippath))//如果压缩包存在删除已有压缩文件
         {
               System.IO.File.Delete(zippath);
         }

            //需要压缩的文件夹
         zc.CreateZip(webRootPath, zippath);



         return File(zc.FileContent(zippath), "application/octet-stream", "附件.zip")  ;
}

 代码：

using ICSharpCode.SharpZipLib.Checksum;
using ICSharpCode.SharpZipLib.Zip;
using System;
using System.IO;
using System.Text;

public class ZipSugar
{

    #region 递归压缩 
    /// <summary>
    /// 递归压缩 
    /// </summary>
    /// <param name="FolderToZip"></param>
    /// <param name="s"></param>
    /// <param name="ParentFolderName"></param>
    private bool ActionFileDictory(string FolderToZip, ZipOutputStream s, string ParentFolderName)
    {
        bool res = true;
        string[] folders, filenames;
        ZipEntry entry = null;
        FileStream fs = null;
        Crc32 crc = new Crc32();
        try
        {
            //创建当前文件夹
            entry=new ZipEntry
            (Path.Combine(ParentFolderName,Path.GetFileName(FolderToZip) + "/"));//加上“/”才会当成是文件夹创建
            s.PutNextEntry(entry);
            s.Flush();
            //先压缩文件，再递归压缩文件夹 
            filenames = Directory.GetFiles(FolderToZip);
            foreach (string file in filenames)
            {
                if (file.Contains(".rar") || file.Contains(".zip")) 
                {
                    continue;
                }
                //打开压缩文件
                fs = File.OpenRead(file);

                byte[] buffer = new byte[fs.Length];
                fs.Read(buffer, 0, buffer.Length);
                entry = new ZipEntry
                (Path.Combine(ParentFolderName, Path.GetFileName(FolderToZip)+"/"+Path.GetFileName(file)));
                entry.DateTime = DateTime.Now;
                entry.Size = fs.Length;
                fs.Close();
                crc.Reset();
                crc.Update(buffer);
                entry.Crc = crc.Value;
                s.PutNextEntry(entry);
                s.Write(buffer, 0, buffer.Length);
            }
        }
        catch
        {
            res = false;
        }
        finally
        {
            if (fs != null)
            {
                fs.Close();
                fs = null;
            }
            if (entry != null)
                entry = null;
            GC.Collect();
            GC.Collect(1);
        }
        folders = Directory.GetDirectories(FolderToZip);
        foreach (string folder in folders)
        {
            if (!ActionFileDictory(folder, s, Path.Combine(ParentFolderName, Path.GetFileName(FolderToZip))))
                return false;
        }
        return res;
    }

    #endregion

    #region 压缩目录

    /// <summary>
    /// 压缩目录
    /// </summary>
    private string ActionFileDictory(string FolderToZip, string ZipedFile, string Password)
    {
        bool res;
        if (!Directory.Exists(FolderToZip))
            return "错误";
        ZipOutputStream s = new ZipOutputStream(File.Create(ZipedFile));
        s.SetLevel(6);
        if (!string.IsNullOrEmpty(Password.Trim()))
            s.Password = Password.Trim();
        res = ActionFileDictory(FolderToZip, s, "");
        s.Finish();
        s.Close();
        if (res)
        {
            return ZipedFile;
        }
        else
        {
            return null;
        }

    }

    #endregion

    #region 压缩文件

    /// <summary>
    /// 压缩文件
    /// </summary>
    /// <param name="FileToZip">要进行压缩的文件名</param>
    /// <param name="ZipedFile">压缩后生成的压缩文件名</param>
    /// <returns></returns>
    private string AcintonFile(string FileToZip, string ZipedFile, string Password)
    {
        //如果文件没有找到，则报错
        if (!File.Exists(FileToZip))
            throw new System.IO.FileNotFoundException("指定要压缩的文件: " + FileToZip + " 不存在!");
        //FileStream fs = null;
        FileStream ZipFile = null;
        ZipOutputStream ZipStream = null;
        ZipEntry ZipEntry = null;
        string res;
        try
        {
            ZipFile = File.OpenRead(FileToZip);
            byte[] buffer = new byte[ZipFile.Length];
            ZipFile.Read(buffer, 0, buffer.Length);
            ZipFile.Close();
            ZipFile = File.Create(ZipedFile);
            ZipStream = new ZipOutputStream(ZipFile);
            if (!string.IsNullOrEmpty(Password.Trim()))
                ZipStream.Password = Password.Trim();
            ZipEntry = new ZipEntry(Path.GetFileName(FileToZip));
            ZipStream.PutNextEntry(ZipEntry);
            ZipStream.SetLevel(6);
            ZipStream.Write(buffer, 0, buffer.Length);
        }
        catch
        {
            res = "错误";
        }
        finally
        {
            if (ZipEntry != null)
            {
                ZipEntry = null;
            }
            if (ZipStream != null)
            {
                ZipStream.Finish();
                ZipStream.Close();
            }
            if (ZipFile != null)
            {
                ZipFile.Close();
                ZipFile = null;
            }
            GC.Collect();
            GC.Collect(1);
        }

        return "成功";
    }

    #endregion

    #region Zip

    /// <summary>
    /// 压缩文件 和 文件夹
    /// </summary>
    public string CreateZip(string FileToZip, string ZipedFile, string Password)
    {
        if (Directory.Exists(FileToZip))
        {
            return ActionFileDictory(FileToZip, ZipedFile, Password);
        }
        else if (File.Exists(FileToZip))
        {
            return AcintonFile(FileToZip, ZipedFile, Password);
        }
        else
        {
            return "失败";
        }
    }

    /// <summary>
    /// 压缩文件 和 文件夹
    /// </summary>
    /// <param name="FileToZip">待压缩的文件或文件夹，全路径格式</param>
    /// <param name="ZipedFile">压缩后生成的压缩文件名，全路径格式</param>
    /// <returns></returns>
    public string CreateZip(string FileToZip, string ZipedFile)
    {
        return CreateZip(FileToZip, ZipedFile, "");
    }

    public byte[] FileContent(string fileName)
    {
        using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
        {
            try
            {
                byte[] buffur = new byte[fs.Length];
                fs.Read(buffur, 0, (int)fs.Length);
                return buffur;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }
    #endregion

}