如何使用HttpWebRequest和HttpWebResponse类下载文件(Cookie、凭证等)
如何使用HttpWebRequest和HttpWebResponse类下载文件(Cookie、凭证等)
提问于 2011-01-15 21:57:35
谢谢，我试过使用HttpWebRequest和HttpWebResponse。
当我通过传递像UserName和密码这样的凭证来请求URL时。
我将在响应中取回会话Id。
在获得会话Id之后，如何进一步。
使用凭证/cookie跟踪经过身份验证的用户。我有确切的网址的文件要下载和凭证。如果你想使用Cookie，我会的。我需要读取File数据并将其写入/保存到指定位置。
我使用的代码是；
string username = "";
string password = "";
string reqString = "https://xxxx.com?FileNAme=asfhasf.mro" + "?" +
"username=" + username + &password=" + password;
byte[] requestData = Encoding.UTF8.GetBytes(reqString);
string s1;
CookieContainer cc = new CookieContainer();
var request = (HttpWebRequest)WebRequest.Create(loginUri);
request.Proxy = null;
request.CookieContainer = cc;
request.Method = "POST";
HttpWebResponse ws = (HttpWebResponse)request.GetResponse();
Stream str = ws.GetResponseStream();
//ws.Cookies
//var request1 = (HttpWebRequest)WebRequest.Create(loginUri);
byte[] inBuf = new byte[100000];
int bytesToRead = (int) inBuf.Length;
int bytesRead = 0;
while (bytesToRead > 0)
{
int n = str.Read(inBuf, bytesRead,bytesToRead);
if (n==0)
break;
bytesRead += n;
bytesToRead -= n;
}
FileStream fstr = new FileStream("weather.jpg", FileMode.OpenOrCreate,
FileAccess.Write);
fstr.Write(inBuf, 0, bytesRead);
str.Close();
fstr.Close();回答 2
Stack Overflow用户
发布于 2011-01-16 13:54:54
我是这样做的：
const string baseurl = "http://www.some......thing.com/";
CookieContainer cookie;第一种方法登录到web服务器并获取会话id：
public Method1(string user, string password) {
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(baseurl);
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
string login = string.Format("go=&Fuser={0}&Fpass={1}", user, password);
byte[] postbuf = Encoding.ASCII.GetBytes(login);
req.ContentLength = postbuf.Length;
Stream rs = req.GetRequestStream();
rs.Write(postbuf,0,postbuf.Length);
rs.Close();
cookie = req.CookieContainer = new CookieContainer();
WebResponse resp = req.GetResponse();
resp.Close();
}另一种方法从服务器获取文件：
string GetPage(string path) {
HttpWebRequest req = (HttpWebRequest)WebRequest.Create(path);
req.CookieContainer = cookie;
WebResponse resp = req.GetResponse();
string t = new StreamReader(resp.GetResponseStream(), Encoding.Default).ReadToEnd();
return IsoToWin1250(t);
}请注意，我将页面作为字符串返回。您最好将其作为bytes[]返回，以便保存到磁盘。如果您的jpeg文件很小(它们通常不是千兆字节大小)，您可以简单地将它们放到内存流中，然后保存到磁盘。在C#中只需要2到3行简单的代码，而不是像你上面提供的那样有潜在危险内存泄漏的30行代码。
Stack Overflow用户
发布于 2019-10-01 20:05:05
public override DownloadItems GetItemStream(string itemID, object config = null, string downloadURL = null, string filePath = null, string)
{
DownloadItems downloadItems = new DownloadItems();
try
{
if (!string.IsNullOrEmpty(filePath))
{
using (FileStream fileStream = new System.IO.FileStream(filePath, System.IO.FileMode.OpenOrCreate, System.IO.FileAccess.Write))
{
if (!string.IsNullOrEmpty(downloadURL))
{
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(downloadURL);
request.Method = WebRequestMethods.Http.Get;
request.PreAuthenticate = true;
request.UseDefaultCredentials = true;
const int BUFFER_SIZE = 16 * 1024;
{
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
using (var responseStream = response.GetResponseStream())
{
var buffer = new byte[BUFFER_SIZE];
int bytesRead;
do
{
bytesRead = responseStream.Read(buffer, 0, BUFFER_SIZE);
fileStream.Write(buffer, 0, bytesRead);
} while (bytesRead > 0);
}
}
fileStream.Close();
downloadItems.IsSuccess = true;
}
}
else
downloadItems.IsSuccess = false;
}
}
}
catch (Exception ex)
{
downloadItems.IsSuccess = false;
downloadItems.Exception = ex;
}
return downloadItems;
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/4699938
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