Nuget 安装：Install-Package ICSharpCode.SharpZipLib.dll
private void WriteZipFile(string[] filesToZip, string writeToFilePath)
{
try
{
Crc32 crc = new Crc32();
ZipOutputStream s = new ZipOutputStream(System.IO.File.Create(writeToFilePath));
s.SetLevel(9); // 0 - store only to 9 - means best compression
for (int i = 0; i < filesToZip.Length; i++)
{
// Must use a relative path here so that files show up in the Windows Zip File Viewer
// .. hence the use of Path.GetFileName(...)
ZipEntry entry = new ZipEntry(Path.GetFileName(filesToZip[i]));
entry.DateTime = DateTime.Now; // Read in the
using (FileStream fs = System.IO.File.OpenRead(filesToZip[i]))
{ byte[] buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length); // set Size and the crc, because the information
// about the size and crc should be stored in the header
// if it is not set it is automatically written in the footer.
// (in this case size == crc == -1 in the header)
// Some ZIP programs have problems with zip files that don't store
// the size and crc in the header.
entry.Size = fs.Length;
fs.Close(); crc.Reset();
crc.Update(buffer);
entry.Crc = crc.Value;
s.PutNextEntry(entry);
s.Write(buffer, 0, buffer.Length);
}
} s.Finish();
s.Close(); }
catch (Exception ex)
{
HttpContext.Trace.Warn(ex.ToString());
}
}
今天经过大文件压缩测试，发现这里有一个内存溢出的bug，当文件大于500M左右时，
byte[] buffer = new byte[fs.Length]; //会发生内存溢出
经查资料，解决方法是，边读文件流边压缩，这样就可以避免Web服务器一次性都到的内存里，如果先把文件压缩到MemoryStream,最后在输出就会消耗大量的内存在MemoryStream里。也就容易引起内存溢出了
private void WriteZipFile(string[] filesToZip, string writeToFilePath)
{
try
{
Stream fs1 = System.IO.File.OpenWrite(writeToFilePath);
ZipOutputStream s = new ZipOutputStream(fs1);
s.SetLevel(9); // 0 - store only to 9 - means best compression
for (int i = 0; i < filesToZip.Length; i++)
{
ZipEntry entry = new ZipEntry(Path.GetFileName(filesToZip[i]));
entry.DateTime = DateTime.Now;
using (var fs = new FileStream(filesToZip[i], FileMode.Open, FileAccess.Read))
{
entry.Size = fs.Length; //这个时候是没用把文件读到内存里的
s.PutNextEntry(entry); byte[] buffer = new byte[10240]; //边读边写
int bytesRead = 0;
while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) > 0)
{
s.Write(buffer, 0, bytesRead);
}
s.CloseEntry();
}
}
s.Finish();
s.Close();
fs1.Close();
}
catch (Exception ex)
{
HttpContext.Trace.Warn(ex.ToString());
}
}
MVC 输出：File(Server.MapPath("文件路径"), "application/zip", "文件名");
WebForm 输出同样要避免500M文件容易出现的内存溢出：
public void DownloadFile(string physicalFilePath)
{
FileStream stream = null;
try
{
stream = new FileStream(physicalFilePath, FileMode.Open, FileAccess.Read, FileShare.Read); byte[] buffer = new byte[10240];
int bytesRead = 0;
while ((bytesRead = stream.Read(buffer, 0, buffer.Length)) > 0)
{
HttpContext.Response.OutputStream.Write(buffer, 0, bytesRead);
}
HttpContext.Response.ContentType = "application/octet-stream ";
HttpContext.Response.AppendHeader("Content-Disposition ", "attachment;filename= " + System.IO.Path.GetFileName(physicalFilePath)); HttpContext.Response.End();
}
finally
{
stream.Close();
}
}