如何透過Request的方式，進行Post網頁，並直接解析該請求網頁的內容

有人的做法是用webClient去做，但是保哥提到透過該方法有以下的缺點：

無法指定 Timeout，所以當網路連不上時，網頁或程式會整個停在那裡很久！

不適合用來下載大量的檔案，高負載的網站也不適合這樣用，即便你用非同步的方式撰寫，也會讓WebClient

因為佔據過多 Threads 而導致效能降低，壹台電腦的 Threads 數是有限制的。

對於較正式的場合，還是建議改用 HttpWebRequest 類別處理。

參考源碼如下：

//指定編碼

Encoding myEncoding = Encoding.GetEncoding("big5");

//宣告要post的變數字串

string param = HttpUtility.UrlEncode("FormID", myEncoding) + "=" + HttpUtility.UrlEncode("ACT011", myEncoding) + "&" + HttpUtility.UrlEncode("SheetNo", myEncoding) + "="+HttpUtility.UrlEncode("200900010001", myEncoding) + "&" + HttpUtility.UrlEncode("ParserRoleID", myEncoding) + "=" + HttpUtility.UrlEncode("1", myEncoding) + "&" + HttpUtility.UrlEncode("BranchNo", myEncoding) + "=" + HttpUtility.UrlEncode("0010", myEncoding) + "&"+ HttpUtility.UrlEncode("SerialNo", myEncoding) + "=" + HttpUtility.UrlEncode("01", myEncoding) + "&" + HttpUtility.UrlEncode("FlowID", myEncoding) + "=" + HttpUtility.UrlEncode("1", myEncoding) + "&"+ HttpUtility.UrlEncode("UserID", myEncoding) + "=" + HttpUtility.UrlEncode("3726", myEncoding);

//對post參數進行編碼

byte[] postBytes = Encoding.ASCII.GetBytes(param);

//宣告HttpWebRequest物件，並指派URL對像

HttpWebRequest req = HttpWebRequest)HttpWebRequest.Create("http://localhost/EFSP7/PostTest.aspx");

req.Method = "POST";

req.ContentType = "application/x-www-form-urlencoded;charset=big5";

req.ContentLength = postBytes.Length;

發送Request，並寫入Post參數

using (Stream reqStream = req.GetRequestStream())

{

reqStream.Write(postBytes, 0, postBytes.Length);

}

//取得Request的回傳串流

using (HttpWebResponse wr = req.GetResponse() as HttpWebResponse)

{

StreamReader tSR = new StreamReader(wr.GetResponseStream(), System.Text.Encoding.Default);

string tResult = tSR.ReadToEnd();

tSR.Close();

try

{

Response.Write(tResult);

}

catch (Exception ex)

{

throw ex;

}

}

參考網址：

http://www.cnblogs.com/webman/archive/2006/11/17/564106.html

http://blog.miniasp.com/post/2010/01/23/Emulate-Form-POST-with-WebClient-class.aspx