How to I do a http post from within a webform -- dotnet faqs

santanbo
12/13/2004 2:59:04 PM

I found one way to do something pretty similar. If you find a better way,
pl. let me know.

In this example WebForm1.aspx goes to WebForm2.aspx via http post.
<code>
********************WebForm1.aspx*****************
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Net;
using System.IO;
using System.Text;

namespace WebApplication5
{
/// <summary>
/// Summary description for WebForm1.
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
WebRequest myRequest =
WebRequest.Create("http://localhost/WebApplication5/WebForm2.aspx");
myRequest.Headers["field1"]="value1";
myRequest.Headers["field2"]="value2";
myRequest.Method="POST";
myRequest.ContentType="text/html";
myRequest.ContentLength=0;
WebResponse resp = myRequest.GetResponse();
Stream ReceiveStream = resp.GetResponseStream();
Encoding encode = System.Text.Encoding.GetEncoding("utf-8");
StreamReader readStream = new StreamReader( ReceiveStream, encode );
string str = readStream.ReadToEnd();
readStream.Close();
resp.Close();
Response.Write(str);
Response.Flush();
}

#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}

********************WebForm2.aspx*****************
public class WebForm2 : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
string field1=(string)Request.Headers["field1"];
string field2=(string)Request.Headers["field2"];
Response.Write("Your value for field1 was " + field1 + " & field2 was " +
field2);
}

#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}

</code>
[quoted text, click to view]

Phillip N Rounds
12/13/2004 4:11:00 PM

I have a webform, from which I have to submit info to another site. Their
instructions are to have a html form, with the following as the submit:
<form method="post" action="http://www.theirsite.htm">
<input type=hidden name="field1" value="value1">
<input type=hidden name="field2> value="value2>
<input type="submit" value="Click Me">

On my web form, I have numerous web controls ( all runat="server"), one of
which is a button which the user must click to prepare to move to the next
site. I would like to add code to this button to simulate the effect of the
form above. How do I do this? I see how I can post the data to the target
site, with say a WebClient, or HttpRequest write, but that doesn't take me
to the new page. I could transfer to the new page, but it doesn't submit
the required info. I could add a html control to the page, but this
wouldn't have access to the web controls, and hence none of the info
collected there.

Thanks in advance

--
Phillip N Rounds
The Cassandra Group, Inc
68 Sand Hill Rd
Flemington NJ 08822
prounds@cassandragroup.com

santanbo
12/14/2004 2:25:02 PM

Hi Philip,

[quoted text, click to view]

Which way are you referring here: Steve's or mine?

Santanu

[quoted text, click to view]

santanbo
12/14/2004 2:35:01 PM

I think document.history.back() in your html string is worth exploring. I
don't know whether it will work as I haven't tried it in this context.

Let me know..

[quoted text, click to view]

Phillip N Rounds
12/14/2004 4:57:31 PM

I would rather not do it that way ( besides, I don't know how to access
values contained in my web controls, and variables I have calculated in th
background from the client side java script, or, conversely, to invoke
client side functions from within the web controls, but that is another
story.)
I have one web control button which has to be invoked to finalize
calcuations on the webform, and it has to be a webform control not a html
control. It seems bad design to have to have a second control to finish the
processing.

From another source, I have tried the following

HttpResponse myResponse = HttpContext.CurrentResponse;
MyResponse.ClearContents();
MyResponse.ClearHeaders();
MyResponse.Output.Flush();
String NewHTML = "<html><body><form name='form1' method='post'
action='http://www.newwebsite.com'>
<input name='field1' type='hidden'
value='abcdefg'>
<input name='field2.... > .... </form>
<script language=javascript>
document.redirect.submit();></script></body></html>";

char[] output = NewHTML.ToCharArray();
MyResponse.Write( outout, 0, output.Length);

This takes me to the appropriate site, and posts all my variables
appropriately. My problem here is that while at the new site, if the user
hits the back button on the browser, it gets sent to the page I just
overwrote, which redirects the user back to the target site.

Thanks for the input

[quoted text, click to view]

Phillip N Rounds
12/14/2004 5:16:56 PM

This doesn't work in my case. The key here is that the web request doesn't
recognize https, which is where I'm going

From another source, I have tried the following

HttpResponse myResponse = HttpContext.CurrentResponse;
MyResponse.ClearContents();
MyResponse.ClearHeaders();
MyResponse.Output.Flush();
String NewHTML = "<html><body><form name='form1' method='post'
action='http://www.newwebsite.com'>
<input name='field1' type='hidden'
value='abcdefg'>
<input name='field2.... > .... </form>
<script language=javascript>
document.redirect.submit();></script></body></html>";

char[] output = NewHTML.ToCharArray();
MyResponse.Write( outout, 0, output.Length);

This takes me to the appropriate site, and posts all my variables
appropriately. My problem here is that while at the new site, if the user
hits the back button on the browser, it gets sent to the page I just
overwrote, which redirects the user back to the target site.

Any suggestions as to how I can get around that would be appreciated.

Thanks for the input

[quoted text, click to view]

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