如何使用WebRequest和/或HTML Agility Pack在Content-Disposition附件中获取文件

Question

我正在开发一个网络爬虫，该爬虫将从网站上下载PDF文件。

我之前检查了网站的源代码，发现下载PDF的按钮实际上是对表单的提交输入。相应地，该表格将检索Content-Disposition标头中的文件。

这是一张照片：

我的问题是，如何使用Web请求（或HTML Agility包）获取此文件。我以这种方式尝试过，但听者返回null。

HttpWebResponse response = (HttpWebResponse)req.GetResponse();
string file = response.Headers["Content-Disposition"];

预先感谢

Answer 1

我已经有了答案，这是我为获取文件所做的事情

response = (HttpWebResponse)request.GetResponse();
stream = response.GetResponseStream();
byte[] retorno = ReadToEnd(stream);
response.Close();
stream.Close();

public static byte[] ReadToEnd(System.IO.Stream stream)
{
    long originalPosition = 0;

    if (stream.CanSeek)
    {
        originalPosition = stream.Position;
        stream.Position = 0;
    }

    try
    {
        byte[] readBuffer = new byte[4096];

        int totalBytesRead = 0;
        int bytesRead;

        while ((bytesRead = stream.Read(readBuffer, totalBytesRead, readBuffer.Length - totalBytesRead)) > 0)
        {
            totalBytesRead += bytesRead;

            if (totalBytesRead == readBuffer.Length)
            {
                int nextByte = stream.ReadByte();
                if (nextByte != -1)
                {
                    byte[] temp = new byte[readBuffer.Length * 2];
                    Buffer.BlockCopy(readBuffer, 0, temp, 0, readBuffer.Length);
                    Buffer.SetByte(temp, totalBytesRead, (byte)nextByte);
                    readBuffer = temp;
                    totalBytesRead++;
                }
            }
        }

        byte[] buffer = readBuffer;
        if (readBuffer.Length != totalBytesRead)
        {
            buffer = new byte[totalBytesRead];
            Buffer.BlockCopy(readBuffer, 0, buffer, 0, totalBytesRead);
        }
        return buffer;
    }
    finally
    {
        if (stream.CanSeek)
        {
            stream.Position = originalPosition;
        }
    }
}

谢谢