下载使用WebRequests PDF文件 [英] Downloading pdf file using WebRequests

问题描述

我想下载一些PDF文件自动地给出一个网址列表

下面是我的代码：

  HttpWebRequest的要求=（HttpWebRequest的）WebRequest.Create（URL）; 
 
 request.Method =GET; 
 
变种编码=新UTF8Encoding（）; 
 
 request.Headers.Add（HttpRequestHeader.AcceptLanguage，EN-GB，连接; Q = 0.5）; 
 request.Headers.Add（HttpRequestHeader.AcceptEncoding，gzip的，放气）; 
 
 request.Accept =text / html的，是application / xhtml + xml的，应用/ XML; Q = 0.9 * / *; Q = 0.8; 
 request.UserAgent =Mozilla的/ 5.0（Windows NT的6.1; WOW64; RV：12.0）的Gecko / 20100101火狐/ 12.0; 
 
 HttpWebResponse RESP =（HttpWebResponse）request.GetResponse（）; 
 
 BinaryReader读者=新BinaryReader（resp.GetResponseStream（））; 
 
的FileStream流=新的FileStream（输出/+与Date.toString（YYYY-MM-DD）+.PDF，FileMode.Create）; 
 
的BinaryWriter作家=新的BinaryWriter（流）; 
 
在
 {
 writer.Write（reader.Read（））（reader.PeekChar（）！= -1）; 
} 
 writer.Flush（）; 
 writer.Close（）; 
  

所以，我知道的第一部分作品。原本我是得到它，并使用TextReader的阅读它 - 但是这给了我损坏的PDF文件（因为PDF文件是二进制文件）

现在如果我运行它，阅读器.PeekChar（）始终是-1并没有任何反应 - 我得到一个空文件

在调试它，我注意到，reader.Read（）实际上是给不同的号码当我调用它 - 所以也许皮克坏

所以，我想的东西很肮脏

 试
 {
，而（真）
 {
 writer.Write（reader.Read（））; 
} 
} 
抓
 {
} 
 writer.Flush（）; 
 writer.Close（）; 
  

现在我越来越与它的一些垃圾一个非常小的文件，但它仍然不是我？在寻找

所以，任何人都可以点我在正确的方向

其他信息：

头并不表明其压缩或其他任何东西。

  HTTP / 1.1 200 OK 
内容类型：应用程序/ PDF 
服务器：Microsoft-IIS / 7.5 
的X技术，通过：ASP.NET 
日期：星期五，8月10日2012 GMT 11时15分48秒
的Content-Length：109809 
  

解决方案

跳过 BinaryReader 和的BinaryWriter ，只输入流复制到输出的FileStream 。简单地说

  VAR文件名=输出/+与Date.toString（YYYY-MM-DD）+.PDF ;使用
（VAR流= File.Create（文件名））
 resp.GetResponseStream（）CopyTo从（流）。 
  

I'm trying to download a number of pdf files automagically given a list of urls.

Here's the code I have:

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);

request.Method = "GET";

var encoding = new UTF8Encoding();

request.Headers.Add(HttpRequestHeader.AcceptLanguage, "en-gb,en;q=0.5");
request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip, deflate");

request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0";

HttpWebResponse resp = (HttpWebResponse)request.GetResponse();

BinaryReader reader = new BinaryReader(resp.GetResponseStream());

FileStream stream = new FileStream("output/" + date.ToString("yyyy-MM-dd") + ".pdf",FileMode.Create);

BinaryWriter writer = new BinaryWriter(stream);

while (reader.PeekChar() != -1)
      {
       writer.Write(reader.Read());
      }
       writer.Flush();
       writer.Close();

So, I know the first part works. I was originally getting it and reading it using a TextReader - but that gave me corrupted pdf files (since pdfs are binary files).

Right now if I run it, reader.PeekChar() is always -1 and nothing happens - I get an empty file.

While debugging it, I noticed that reader.Read() was actually giving different numbers when I was invoking it - so maybe Peek is broken.

So I tried something very dirty

try
{
 while (true)
   {
    writer.Write(reader.Read());
    }
 }
   catch
      {
      }
 writer.Flush();
 writer.Close();

Now I'm getting a very tiny file with some garbage in it, but its still not what I'm looking for.

So, anyone can point me in the right direction?

Additional Information:

The header doesn't suggest its compressed or anything else.

HTTP/1.1 200 OK
Content-Type: application/pdf
Server: Microsoft-IIS/7.5
X-Powered-By: ASP.NET
Date: Fri, 10 Aug 2012 11:15:48 GMT
Content-Length: 109809

解决方案

Skip the BinaryReader and BinaryWriter and just copy the input stream to the output FileStream. Briefly

var fileName = "output/" + date.ToString("yyyy-MM-dd") + ".pdf";
using (var stream = File.Create(fileName))
  resp.GetResponseStream().CopyTo(stream);

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