使用HttpWebRequest的POST取得网页内容(异步操作)2篇集合
这一看不要紧，搞得我一头雾水。上网上去问，大家给出的方法都是用多线程来搞定。这个在下一个帖子中我会发上来。这里主要说一下用BeginGetResponse，EndGetResponse来完成 异步操作。
先说一下，我的要求：
一，从数据库中取出所有的IP
二，利用 httpwebrequest的post方法在网上取得它的相应地址。当然了，是用post还是用get主要是看网上的网站是用什么方法来传值。
三，将所得到的值写入数据库
下面我把我的代码放上来，前台没有什么东西，运行的结果是直接写入数据库，
数据库名为DBCT_Dev
省份表S_Province，其中ProvinceName为省分名。ProvinceCode为省分相对的Code
市级表S_City,其中CityName为市名。ZipCode为市相对应的Code。
这二个表是在网上找到的，有很多中国省市关联表，大家可以去下一个。
用户IP表UserCode，其中Code为其IP所对应的省市Code，IP为用户的IP地址。
好了，下面是代码
- using System;
- using System.Collections.Generic;
- using System.Linq;
- using System.Web;
- using System.Web.UI;
- using System.Web.UI.WebControls;
- using System.IO;
- using System.Text;
- using System.Net;
- using System.Threading;
- using System.Data;
- using System.Collections;
- namespace getPageValue
- {
- public partial class two : System.Web.UI.Page
- {
- public DBClass db = new DBClass();//我自己写的一个类，主要是用来做一些数据库操作的，你可以使用你自己的
- public static Hashtable ht = new Hashtable();
- private static ManualResetEvent allDone = new ManualResetEvent(false);
- public static string singleid;
- protected void Page_Load(object sender, EventArgs e)
- {
- if (!Page.IsPostBack)
- {
- //将数据库中Code为空ip不为空的记录存入，放到一个DataTable中。
- string strsql = "select * from UserCode where UserIP<>'' and (Code is null or code = '')";
- DataTable dt = db.GetDataTable(strsql);
- for (int i = 0; i < dt.Rows.Count; i++)
- {
- //调用转化方法
- getPost(dt.Rows[i]["id"].ToString());
- //每次调用间隔一秒，通过实验得到，如果你的数据量大，最好间隔5秒
- Thread.Sleep(1000);
- }
- Thread.Sleep(5000);
- dt.Dispose();
- //调用将转化信息存入数据库的方法
- ChangeUserCode();
- }
- }
- public void getPost(string id)
- {
- //定义变量
- //singleid 传入的用户信息ID
- //singleip 根据用户信息ID，而取到的IP
- //strAction post必传值之一
- //strCode 传入用户信息表中的code值
- //
- singleid = id;
- //通过GetSingleValue方法，得到相应的值，这里GetSingleValue（表名，要得到的值，条件语句）
- string singleip = db.GetSingleValue("UserCode", "UserIP", "id=" + singleid).Trim();
- string strAction = "2";
- string strCode = "";
- //将得到的post值，转化为byte型
- ASCIIEncoding encoding = new ASCIIEncoding();
- string postData = "ip=" + singleip;
- postData += "&action=" + strAction;
- byte[] data = encoding.GetBytes(postData);
- //建立HttpWebRequest
- HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create("http://www2.ip138.com/ips8.asp");
- myRequest.Method = "POST";
- myRequest.ContentType = "application/x-www-form-urlencoded";
- myRequest.ContentLength = data.Length;
- Stream myStream = myRequest.GetRequestStream();
- myStream.Write(data, 0, data.Length);
- myStream.Close();
- //开始调用异步操作
- myRequest.BeginGetResponse(new AsyncCallback(ReadCallback), myRequest);
- allDone.WaitOne();
- }
- private void ReadCallback(IAsyncResult asynchronousResult)
- {
- HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
- //Stream postStream = request.EndGetResponse(asynchronousResult);
- //异步回调方法使用 EndGetResponse 方法返回实际的 WebResponse。
- HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
- Stream streamResponse = response.GetResponseStream();
- StreamReader streamRead = new StreamReader(streamResponse, Encoding.Default);
- string content = streamRead.ReadToEnd();
- //string con = responseString.Substring(responseString.IndexOf(" 本站主数据") + 6, responseString.IndexOf("</li><li>参考数据 一") - responseString.IndexOf("本站主数据") - 1);
- //Response.Write(con + "<br>");
- //判断是否是有省市的信息，如果信息中有省，市，则进行存入数据库，如为127.0.0.1，是直接给本省code。其它信息，则不给记录
- string singleip = "";
- string strCode = "";
- if (singleip == "127.0.0.1")
- {
- strCode = "0008";
- }
- else
- {
- if (content.IndexOf("省") == -1 && content.IndexOf("市") == -1 && singleid != "127.0.0.1")
- {
- if (content.IndexOf("查询太频繁") != -1)
- {
- strCode = "查询太频繁";
- }
- else
- {
- strCode = "0035";
- }
- }
- else
- {
- if (content.IndexOf("省") != -1)
- {
- string con = content.Substring(content.IndexOf("本站主数据") + 6, content.IndexOf("</li><li>参考数据一") - content.IndexOf("本站主数据") - 1);
- string strpro = con.Substring(0, con.IndexOf("省") + 1);
- strCode = db.GetSingleValue("S_Province", "ProvinceCode", "ProvinceName='" + strpro + "'").Trim();
- //strCode = strpro;
- }
- if (content.IndexOf("市") != -1)
- {
- string con = content.Substring(content.IndexOf("本站主数据") + 6, content.IndexOf("</li><li>参考数据一") - content.IndexOf("本站主数据") - 1);
- string strpro = con.Substring(con.IndexOf("省") + 1, con.IndexOf("市") - con.IndexOf("省"));
- strCode += db.GetSingleValue("S_City", "ZipCode", "CityName='" + strpro + "'").Trim(); ;
- }
- }
- }
- if (strCode == "")
- {
- strCode = "0035";
- }
- //将信息存入hashtable
- ht.Add(singleid, strCode);
- streamResponse.Close();
- streamRead.Close();
- response.Close();
- allDone.Set();
- }
- public void ChangeUserCode()
- {
- if (ht.Count > 0)
- {
- foreach (DictionaryEntry objDE in ht)
- {
- string strsql = "update UserCode set Code='" + objDE.Value.ToString() + "' where id=" + objDE.Key.ToString() + "";
- try
- {
- db.ExecuteSql(strsql);
- }
- catch
- {
- continue;
- }
- }
- }
- }
- }
- }
- using System;
- using System.Net;
- using System.IO;
- using System.Text;
- using System.Threading;
- class HttpWebRequestBeginGetRequest
- {
- public static ManualResetEvent allDone = new ManualResetEvent(false);
- public static void Main()
- {
- // Create a new HttpWebRequest object.
- HttpWebRequest request=(HttpWebRequest) WebRequest.Create("http://www.contoso.com/example.aspx");
- // Set the ContentType property.
- request.ContentType="application/x-www-form-urlencoded";
- // Set the Method property to 'POST' to post data to the URI.
- request.Method = "POST";
- // Start the asynchronous operation.
- request.BeginGetRequestStream(new AsyncCallback(ReadCallback), request);
- // Keep the main thread from continuing while the asynchronous
- // operation completes. A real world application
- // could do something useful such as updating its user interface.
- allDone.WaitOne();
- // Get the response.
- HttpWebResponse response = (HttpWebResponse)request.GetResponse();
- Stream streamResponse = response.GetResponseStream();
- StreamReader streamRead = new StreamReader(streamResponse);
- string responseString = streamRead.ReadToEnd();
- Console.WriteLine(responseString);
- // Close the stream object.
- streamResponse.Close();
- streamRead.Close();
- // Release the HttpWebResponse.
- response.Close();
- }
- private static void ReadCallback(IAsyncResult asynchronousResult)
- {
- HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
- // End the operation.
- Stream postStream = request.EndGetRequestStream(asynchronousResult);
- Console.WriteLine("Please enter the input data to be posted:");
- string postData = Console.ReadLine ();
- // Convert the string into a byte array.
- byte[] byteArray = Encoding.UTF8.GetBytes(postData);
- // Write to the request stream.
- postStream.Write(byteArray, 0, postData.Length);
- postStream.Close ();
- allDone.Set();
- }
- }
- ----------------------------------------------------------------------------------------------------------
-
C# HttpWebRequest异步人气:44 分类: C#编程 来源:互联网
----------------------------Un Test-------------------------
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Threading;
using System.IO;
namespace WebReqHtml
{
internal class WebReqState
{
public byte[] Buffer;
public MemoryStream ms;
public const int BufferSize = 1024;
public Stream OrginalStream;
public HttpWebResponse WebResponse;
public WebReqState()
{
Buffer = new byte[1024];
ms = new MemoryStream();
}
}
public delegate void ReadDataComplectedEventHandler(byte[] data);
class HtmlFromWebReq
{
private Uri url;
public event ReadDataComplectedEventHandler OnReadDataComplected;
public HtmlFromWebReq(string absoluteUrl)
{
url = new Uri(absoluteUrl);
}
protected void readDataCallback(IAsyncResult ar)
{
WebReqState rs = ar.AsyncState as WebReqState;
int read = rs.OrginalStream.EndRead(ar);
if (read > 0)
{
rs.ms.Write(rs.Buffer, 0, read);
rs.OrginalStream.BeginRead(rs.Buffer, 0, WebReqState.BufferSize, new AsyncCallback(readDataCallback), rs);
}
else
{
rs.OrginalStream.Close();
rs.WebResponse.Close();
if (OnReadDataComplected != null)
{
OnReadDataComplected(rs.ms.ToArray());
}
}
}
protected void responseCallback(IAsyncResult ar)
{
HttpWebRequest req = ar.AsyncState as HttpWebRequest;
if (req == null)
return;
HttpWebResponse response = req.EndGetResponse(ar) as HttpWebResponse;
if (response.StatusCode!= HttpStatusCode.OK)
{
response.Close();
return;
}
WebReqState st=new WebReqState();
st.WebResponse = response;
Stream repsonseStream = response.GetResponseStream();
st.OrginalStream = repsonseStream;
repsonseStream.BeginRead(st.Buffer, 0, WebReqState.BufferSize, new AsyncCallback(readDataCallback), st);
}
public void BeginCreateHtml()
{
HttpWebRequest req = HttpWebRequest.Create(url.AbsoluteUri) as HttpWebRequest;
req.BeginGetResponse( new AsyncCallback(responseCallback), req);
}
}
}