利用了xmlhttp，实现代码比较简单具体实现如下：
首先bin文件引入，com->microsoft xml v3.0
具体代码如下:
protected void Button1_Click(object sender, EventArgs e) { string FileNames = "201406251824392435.pdf", ContentType = ""; string houzhui = FileNames.Substring(FileNames.LastIndexOf(".")); ContentType = checktype(FileNames); string Url = "http://xxx.xxx.xxx.xxx:8089/upfile/wenku/" + FileNames;//域名或者ip地址 string StringFileName = Url.Substring(Url.LastIndexOf("/") + 1); string StringFilePath = Request.PhysicalApplicationPath; if (!StringFilePath.EndsWith("/")) StringFilePath += "/"; try { MSXML2.XMLHTTP _xmlhttp = new MSXML2.XMLHTTPClass(); _xmlhttp.open("GET", Url, false, null, null); _xmlhttp.send(""); if (_xmlhttp.readyState == 4)//数据接收完毕 { if (_xmlhttp.status == 200)//是否返回正确数据 { HttpContext.Current.Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode("测试" + houzhui, System.Text.Encoding.UTF8)); HttpContext.Current.Response.ContentType = ContentType; HttpContext.Current.Response.BinaryWrite((byte[])_xmlhttp.responseBody);//输出二进制到浏览器 HttpContext.Current.Response.Flush(); HttpContext.Current.Response.End(); } else { Response.Write("错误：" + _xmlhttp.statusText + " 未找到要下载的文件!"); } } else { Response.Write("错误：" + _xmlhttp.statusText + " 请求的http地址不对！"); Response.End(); } } catch (Exception ex) { Response.Write("错误：无法找到请求的资源！"); Response.End(); } }
返回mime类型：
private static string checktype(string filename) { string ContentType; string houzhui = filename.Substring(filename.LastIndexOf(".") + 1).Trim().ToLower(); switch (houzhui) { case ".asf": ContentType = "video/x-ms-asf "; break; case ".avi": ContentType = "video/avi "; break; case ".doc": ContentType = "application/msword "; break; case ".zip": ContentType = "application/zip "; break; case ".xls": ContentType = "application/vnd.ms-excel "; break; case ".gif": ContentType = "image/gif "; break; case ".jpg": ContentType = "image/jpeg "; break; case "jpeg": ContentType = "image/jpeg "; break; case ".wav": ContentType = "audio/wav "; break; case ".mp3": ContentType = "audio/mpeg3 "; break; case ".mpg": ContentType = "video/mpeg "; break; case ".mepg": ContentType = "video/mpeg "; break; case ".rtf": ContentType = "application/rtf "; break; case ".html": ContentType = "text/html "; break; case ".htm": ContentType = "text/html "; break; case ".txt": ContentType = "text/plain "; break; case ".pdf": ContentType = "application/pdf"; break; default: ContentType = "application/octet-stream "; break; } return ContentType; }
下载文件并保存到本机：
/// <summary>
/// 获取远程文件到本地
/// </summary>
/// <param name="url">远程文件地址</param>
/// <param name="path">本地路径</param>
private static void DownUrltoFile(string url, string path)
{
string Cookie = String.Empty;
String refer = url.Substring(0, url.LastIndexOf("/") + 1);
System.Net.HttpWebRequest req = System.Net.HttpWebRequest.Create(url) as System.Net.HttpWebRequest;
req.AllowAutoRedirect = false;
req.Referer = refer;
req.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13";
System.Net.HttpWebResponse res = req.GetResponse() as System.Net.HttpWebResponse;
System.Net.WebHeaderCollection headers = res.Headers;
String newUrl = "";
if ((res.StatusCode == System.Net.HttpStatusCode.Found) ||
(res.StatusCode == System.Net.HttpStatusCode.Redirect) ||
(res.StatusCode == System.Net.HttpStatusCode.Moved) ||
(res.StatusCode == System.Net.HttpStatusCode.MovedPermanently))
{
newUrl = headers["Location"];
newUrl = newUrl.Trim();
}
if (headers["Set-Cookie"] != null)
{
Cookie = headers["Set-Cookie"];
}
res.Close();
req = null;
String fileName = newUrl.Substring(newUrl.LastIndexOf("/") + 1);
req = System.Net.HttpWebRequest.Create(url) as System.Net.HttpWebRequest;
req.AllowAutoRedirect = true;
req.Referer = url;
req.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13";
res = req.GetResponse() as System.Net.HttpWebResponse;
System.IO.Stream stream = res.GetResponseStream();
byte[] buffer = new byte[32 * 1024];
int bytesProcessed = 0;
System.IO.FileStream fs = System.IO.File.Create(HttpContext.Current.Server.MapPath(path));
int bytesRead;
do
{
bytesRead = stream.Read(buffer, 0, buffer.Length);
fs.Write(buffer, 0, bytesRead);
bytesProcessed += bytesRead;
}
while (bytesRead > 0);
fs.Flush();
fs.Close();
res.Close();
}
.net 直接输出远程文件到浏览器和下载文件保存到本机,布布扣,bubuko.com
原文：http://www.cnblogs.com/sishahu/p/3809654.html