In the absence of the content described in the topic, it is supposed to be a very simple thing, but when really started to find that there are many problems
Now write it down here, for the same level of reference as I do.
Refer to the article before writing this article
Welcome to CSDN Forum Reader: CSDN Reader (with full source code) Latest version: 20070212
Http://www.cnblogs.com/feiyun0112/archive/2006/09/20/509783.html
C # keeps the post data in the same session through WebRequest http://blog.csdn.net/crabo/archive/2005/12/08/547092.aspx
C # Simulates a click of a button in an ASP. NET page, making a request to the Web server
It is primarily about organizing the data to be submitted and then submitting it as post.
Suppose we have the following page
1<%@ Page language= "C #" autoeventwireup= "true" codefile= "Default.aspx.cs" inherits= "_default"%>
2
3<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
4
567 <title> Untitled Page </title>
89<body>
Ten <form id= "Form1" runat= "Server" >
<div>
<table>
<tr>
<td> Name: </td><td><asp:textbox id= "txtname" runat= "Server" ></ASP:TEXTBOX></TD&G T
</tr>
<tr>
<td> Nickname: </td><td><asp:textbox id= "txtpwd" runat= "Server" textmode= "Password" width= "149px" & Gt;</asp:textbox></td>
</tr>
</table>
<asp:button id= "btnupdate" runat= "Server" text= "Longon" onclick= "Btnupdate_click" width= "60px"/>
<asp:button id= "btnclose" runat= "Server" onclick= "btnClose_Click" text= "Close"/><br/>
22
</div>
</form>
25</body>
26
When you use IE to access this page, you can get the following output
1
2
3<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
4
567 Untitled Page
8</title>9<body>
<form name= "Form1" method= "post" action= "default.aspx" Id= "Form1" >
11<div>
12<input type= "hidden" name= "__viewstate" id= "__viewstate" value= "/ Wepdwukmtg4oda4nde0nmrk6ma0macjkrrnlglfo4qynezoxy4= "/>
13</div>
14
<div>
<table>
<tr>
<td> Name: </td><td><input name= "txtname" type= "text" id= "Txtname"/></td>
</tr>
<tr>
<td> Nickname: </td><td><input name= "txtpwd" type= "password" id= "txtpwd" style= "WIDTH:149PX;"/> ;</td>
</tr>
</table>
<input type= "Submit" Name= "Btnupdate" value= "Logon" id= "btnupdate" style= "width:60px;"/>
<input type= "Submit" Name= "Btnclose" value= "Close" id= "btnclose"/><br/>
26
</div>
28
29<div>
30
<input type= "hidden" name= "__eventvalidation" id= "__eventvalidation" value= "/wewbqkcopufdglehisfcwkd+ 7qddglynaildakt+pmacjleqitxmfque9lk49yoxhv2otzq "/>
32</div></form>
33</body>
3435
From the above code can be seen in addition to Txtname,txtpwd and two buttons, more than two __viewstate,__eventvalidation these four forms need to be submitted to, to simulate which button, which button is added to the value of the form, such as: Btnupdate=logon
When stitching the submitted string, note that the System.Web.HttpUtility.UrlEncode method is used to convert the URL-encoded string.
Here is the submission data for the btnupdate button on this page
1 string __viewstate = "/wepdwukmtg4oda4nde0nmrk6ma0macjkrrnlglfo4qynezoxy4=";
2 string __eventvalidation = "/wewbqkcopufdglehisfcwkd+7qddglynaildakt+pmacjleqitxmfque9lk49yoxhv2otzq";
3
4 __viewstate = System.Web.HttpUtility.UrlEncode (__viewstate);
5
6 __eventvalidation = System.Web.HttpUtility.UrlEncode (__eventvalidation);
7
8 String strpostdata = String.Format ("__viewstate={0}&txtname={1}&txtpwd={2}&btnupdate=longon&__ EVENTVALIDATION={3} "
9, __viewstate, This.txtName.Text, This.txtPassword.Text, __eventvalidation
10);
Then create a HttpWebRequest object, set the Commit method to post, and then write the string prepared above into the request data stream
Basically, yes.
If you need to save the session when accessing different pages, you need to set the Cookiecontainer property of the HttpWebRequest object to ensure that each set of Cookiecontainer is the same object.
Here is the class that makes the request to the Web page and gets the returned data
read Web page content
Use the following method
1private Webpagereader webreader = new Webpagereader ();
2
3string __viewstate = "/wepdwukmtg4oda4nde0nmrk6ma0macjkrrnlglfo4qynezoxy4=";
4string __eventvalidation = "/wewbqkcopufdglehisfcwkd+7qddglynaildakt+pmacjleqitxmfque9lk49yoxhv2otzq";
5
6__viewstate = System.Web.HttpUtility.UrlEncode (__viewstate);
7
8__eventvalidation = System.Web.HttpUtility.UrlEncode (__eventvalidation);
9
10string strpostdata = String.Format ("__viewstate={0}&txtname={1}&txtpwd={2}&btnupdate=longon&__ EVENTVALIDATION={3} "
One, __viewstate, This.txtName.Text, This.txtPassword.Text, __eventvalidation
12);
13string strhtml;
14
15try
16{
+ Do
18{
strHTML = webreader.gethtml ("http://localhost:3517/WebSite1/Default.aspx", strpostdata);
(webreader.iskeepalive);
21st
22
This.richTextBox1.Text = strhtml;
24}
25catch (Exception ex)
26{
if (ex. InnerException = null)
{
MessageBox.Show (ex. Message + "/n" + ex. Innerexception.message);
30}
-Else
{
MessageBox.Show (ex. Message);
34}
+}
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