HttpWebRequest 请求PDF文件，并下载到本地

private void OutPDFStream(HttpContext context, string sPDF_Url)

{

HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create(sPDF_Url);

req.Method = "GET";

using (WebResponse wr = req.GetResponse())

{

StreamReader responseStream = new StreamReader(wr.GetResponseStream(), Encoding.UTF8);

int length = (int)wr.ContentLength;

byte[] bs = new byte[length];

HttpWebResponse response = wr as HttpWebResponse;

Stream stream = response.GetResponseStream();

//读取到内存

MemoryStream stmMemory = new MemoryStream();

byte[] buffer1 = new byte[length];

int i;

while ((i = stream.Read(buffer1, 0, buffer1.Length)) > 0)

{

stmMemory.Write(buffer1, 0, i);

}

byte[] arraryByte = stmMemory.ToArray();

stmMemory.Close();

context.Response.Clear();

//写入到本地

context.Response.AddHeader("Content-Disposition", "attachment;FileName=out.pdf");

context.Response.ContentType = "application/pdf";

context.Response.AddHeader("Content-Length", length.ToString());

context.Response.OutputStream.Write(arraryByte, 0, arraryByte.Length);

context.Response.End();

}

}