/// <summary>
/// 打包下载
/// </summary>
/// <param name="packFolderPath">需要打包的文件夹所在路径</param>
/// <param name="fileNames">需要打包的文件集合（文件名）</param>
/// <param name="zipFileName">打包后显示的文件名</param>
public static void FilePackDownload(string packFolderPath, List <string> fileNames, string zipFileName)
{
using (Ionic.Zip.ZipFile zip = new Ionic.Zip.ZipFile(System.Text.Encoding.Default))//解决中文乱码问题
{
HttpContext httpContext = HttpContext.Current;
httpContext.Response.Clear();
httpContext.Response.ContentType = "application/zip";
//兼容火狐和IE11的浏览器下载
string packFileName = "";
if (httpContext.Request.Headers["USER-AGENT"].IndexOf("MSIE") < 0 &&
httpContext.Request.Headers["USER-AGENT"].IndexOf("like Gecko") < 0)
{
packFileName = "=?UTF-8?B?" + ALEncrypt.Base64EnCode(zipFileName) + "?=";
}
else
{
packFileName = HttpUtility.UrlEncode(zipFileName, Encoding.UTF8);
}
httpContext.Response.AddHeader("content-disposition", "filename=" + packFileName);
zip.AddDirectory(packFolderPath);
foreach (string item in fileNames)
{
try
{
zip.AddFile(item);
}
catch (Exception err)
{
ALMessage.RegMsg("打包下载失败，具体原因：" + err.Message);
}
}
zip.Save(httpContext.Response.OutputStream);
}
}
/// <summary>
/// 文件下载
/// </summary>
/// <param name="filePath">所需下载文件的绝对路径</param>
/// <param name="speed">限制速度以Byte为单位,若限制为200KB的下载速度则为1024 * 200</param>
public static void FileDownload(string filePath, long speed, string downloadFileName, string mime)
{
HttpContext httpContext = HttpContext.Current;
try
{
//验证：HttpMethod，为防止回传下载页面变成空白.只允许get下载
switch (httpContext.Request.HttpMethod.ToUpper())
{
//目前只支持GET和HEAD方法
case "GET":
case "HEAD":
break;
default:
httpContext.Response.StatusCode = 501;
return;
}
//验证：请求的文件是否存在
if (!System.IO.File.Exists(filePath))
{
httpContext.Response.StatusCode = 404;
return;
}
//定义局部变量
long startBytes = 0;
int packSize = 1024 * 10; //分块读取，每块10K bytes
string fileName = downloadFileName;
if (string.IsNullOrEmpty(fileName))
{
fileName = Path.GetFileName(filePath);
}
FileStream myFile = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
BinaryReader br = new BinaryReader(myFile);
long fileLength = myFile.Length;
int sleep = (int)Math.Ceiling(1000.0 * packSize / speed); //毫秒数：读取下一数据块的时间间隔
string lastUpdateTiemStr = System.IO.File.GetLastWriteTimeUtc(filePath).ToString("r");
string eTag = HttpUtility.UrlEncode(fileName, Encoding.UTF8) + lastUpdateTiemStr; //便于恢复下载时提取请求头;
//验证：文件是否太大(2G)
if (myFile.Length > Int32.MaxValue)
{
httpContext.Response.StatusCode = 413;//请求实体太大
return;
}
//对应响应头ETag：文件名+文件最后修改时间
if (httpContext.Request.Headers["If-Range"] != null)
{
//----------上次被请求的日期之后被修改过--------------
if (httpContext.Request.Headers["If-Range"].Replace("\"", "") != eTag)
{
//文件修改过
httpContext.Response.StatusCode = 412;//预处理失败
return;
}
}
try
{
//添加重要响应头、解析请求头、相关验证
httpContext.Response.Clear();
httpContext.Response.Buffer = false;
httpContext.Response.AddHeader("Content-MD5", ALEncrypt.Md5(myFile.ToString())); //用于验证文件
httpContext.Response.AddHeader("Accept-Ranges", "bytes"); //重要：续传必须
httpContext.Response.AppendHeader("ETag", "\"" + eTag + "\""); //重要：续传必须
httpContext.Response.AppendHeader("Last-Modified", lastUpdateTiemStr); //把最后修改日期写入响应
if (string.IsNullOrEmpty(mime))
{
httpContext.Response.ContentType = "application/octet-stream";//MIME类型：匹配任意文件类型
}
else
{
httpContext.Response.ContentType = mime;
}
if (httpContext.Request.Headers["USER-AGENT"].IndexOf("MSIE") < 0 &&
httpContext.Request.Headers["USER-AGENT"].IndexOf("like Gecko") < 0)
{
fileName = "=?UTF-8?B?" + ALEncrypt.Base64EnCode(fileName) + "?=";
}
else
{
fileName = HttpUtility.UrlEncode(fileName, Encoding.UTF8).Replace("+", "%20");
}
httpContext.Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);
httpContext.Response.AddHeader("Content-Length", (fileLength - startBytes).ToString());
httpContext.Response.AddHeader("Connection", "Keep-Alive");
httpContext.Response.ContentEncoding = Encoding.UTF8;
if (httpContext.Request.Headers["Range"] != null)
{
//------如果是续传请求，则获取续传的起始位置，即已经下载到客户端的字节数------
httpContext.Response.StatusCode = 206; //重要：续传必须，表示局部范围响应。初始下载时默认为200
string[] range = httpContext.Request.Headers["Range"].Split(new char[] { '=', '-' }); //"bytes=1474560-"
startBytes = Convert.ToInt64(range[1]); //已经下载的字节数，即本次下载的开始位置
if (startBytes < 0 || startBytes >= fileLength)
{
return;
}
}
//如果是续传请求，告诉客户端本次的开始字节数，总长度，以便客户端将续传数据追加到startBytes位置后
if (startBytes > 0)
{
httpContext.Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength - 1, fileLength));
}
//向客户端发送数据块
br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
//分块下载，剩余部分可分成的块数
int maxCount = (int)Math.Ceiling((fileLength - startBytes + 0.0) / packSize);
//客户端未中断连接，并且数据没有传输完.则一直传输
for (int i = 0; i < maxCount && httpContext.Response.IsClientConnected; i++)
{
httpContext.Response.BinaryWrite(br.ReadBytes(packSize));
httpContext.Response.Flush();
if (sleep > 1)
{
Thread.Sleep(sleep);
}
}
}
catch (Exception ex)
{
throw ex;
}
finally
{
br.Close();
myFile.Close();
}
}
catch (Exception ex)
{
throw ex;
}
}