Một số thao tác với httpwebrequest

Mộột sộố thao tác vớối HttpWebRequest


Lấốy nộội dung trang web (1)

using System;
using System.IO;
using System.Net;
using System.Text;
class WebFetch
{
static void Main(string[] args)
{
// used to build entire input
StringBuilder sb = new StringBuilder(); 
// used on each read operation
byte[]

buf = new byte[8192];


Lấốy nộội dung trang web (2)

// prepare the web page we will be asking for
HttpWebRequest request = (HttpWebRequest) WebRequest.Create(""); 
// execute the request
HttpWebResponse response = (HttpWebResponse)
// we will read data via the response stream
Stream resStream = response.GetResponseStream(); 

request.GetResponse(); 

Lấốy nộội dung trang web (3)

string tempString = null;
int

count

= 0; 

do {
// fill the buffer with data
count = resStream.Read(buf, 0, buf.Length); 

if (count != 0)

{// translate from bytes to ASCII text

Encoding.ASCII.GetString(buf, 0, count); 
// continue building the string
sb.Append(tempString);
}
} while (count > 0); // any more data to read?

// make sure we read some data

tempString =

Lấốy nộội dung trang web (4)

// print out page source
}
}

Console.WriteLine(sb.ToString());


Giaả lấộp sựộ kiệộn vớối form (1)

action=" method="post">
<input type="hidden" name="cmd" value="_cart">
<input type="hidden" name="business" value="">
<input type="hidden" name="item_name" value="HTML book">
<input type="hidden" name="amount" value="24.99">
<input type="image" src=" />border="0" name="submit" alt="Make payments with PayPal!">
<input type="hidden" name="add" value="1">
</form>


Giaả lấộp sựộ kiệộn vớối form (2)

private void OnPostInfoClick(object sender, System.EventArgs e)
{
string strId = UserId_TextBox.Text;
string strName = Name_TextBox.Text;
ASCIIEncoding encoding=new ASCIIEncoding();
string postData="userid="+strId;

postData += ("&username="+strName);
byte[] data = encoding.GetBytes(postData);


Giaả lấộp sựộ kiệộn vớối form (3)

// Prepare web request...
HttpWebRequest myRequest =
(HttpWebRequest)WebRequest.Create("http://localhost/MyIdentity/Default.aspx");
myRequest.Method = "POST";
myRequest.ContentType="application/x-www-form-urlencoded";
myRequest.ContentLength = data.Length;
Stream newStream=myRequest.GetRequestStream();
// Send the data.
newStream.Write(data,0,data.Length);
newStream.Close();
}


Xác điộn h giá triộ Accept-Encoding header

obRequest.Headers.Add("Accept-Encoding", "gzip");

String strEncoding = obResponse.ContentEncoding;
if (String.Compare("gzip", strEncoding, true) == 0)
{
// Unzip the response stream
}

Simple retrieval of Web data over HTTP.

string lcUrl = " ";
// *** Establish the request
HttpWebRequest loHttp =
(HttpWebRequest) WebRequest.Create(lcUrl);
// *** Set properties
loHttp.Timeout = 10000;

// 10 secs

loHttp.UserAgent = "Code Sample Web Client";
// *** Retrieve request info headers
HttpWebResponse loWebResponse = (HttpWebResponse) loHttp.GetResponse();
Encoding enc = Encoding.GetEncoding(1252); // Windows default Code Page
StreamReader loResponseStream =
new StreamReader(loWebResponse.GetResponseStream(),enc);
string lcHtml = loResponseStream.ReadToEnd();
loWebResponse.Close();
loResponseStream.Close();


POSTing data to the Web Server (1)

string lcUrl = " />HttpWebRequest loHttp =
(HttpWebRequest) WebRequest.Create(lcUrl);
 
// *** Send any POST data
string lcPostData =
"Name= " + HttpUtility.UrlEncode("Rick Strahl") +

"&Company=" + HttpUtility.UrlEncode("West Wind ");
 


POSTing data to the Web Server (2)

loHttp.Method= "POST";
byte [] lbPostBuffer = System.Text.
Encoding.GetEncoding(1252).GetBytes(lcPostData);
loHttp.ContentLength = lbPostBuffer.Length;
 
Stream loPostData = loHttp.GetRequestStream();
loPostData.Write(lbPostBuffer,0,lbPostBuffer.Length);
loPostData.Close();


POSTing data to the Web Server (3)

HttpWebResponse loWebResponse = (HttpWebResponse)
loHttp.GetResponse();
 
Encoding enc = System.Text.Encoding.GetEncoding(1252);
 
StreamReader loResponseStream =
new StreamReader(loWebResponse.GetResponseStream(),enc);
 
string lcHtml = loResponseStream.ReadToEnd();
 
loWebResponse.Close();
loResponseStream.Close();

Authentication

 WebRequest.Credentials = new NetworkCredential("username","password");

 WebRequest.Credentials = CredentialCache.DefaultCredentials


Proxy Server Configuration

// pass Proxy string and bypass local machine
WebProxy loProxy = new WebProxy(":8080",true);
 
// ** ByPassList
string[] cByPass = new string[2];
cByPass[1] = "";
cByPass[2] = http://192.0.0.1
 
loProxy.BypassList = cByPass;
 
// ** Proxy Authentication
loProxy.Credentials = new NetworkCredential("proxyusername","pass");
 
Request.Proxy = loProxy;


Proxy Server Configuration

Request.Proxy = new WebProxy(

":8080",true,cBypass,new NetworkCredential(…) );