8

I have an ASP.Net Page, aspx with its default form.

I have a Submit Button for it. Upon clicking, it will post the data to itself. In other words, Button Click Event() from code behind will execute the necessary.

After that, I would like to post the same data to another ASp.Net Page, aspx from another domain.

So, how can I do it?

I tried creating a Form in Button Click Event and a javascript to Submit the Form so that it will post. But the Form is not appearing hence there is already aForm` on the page.

Is there anyway to do it?

william
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5 Answers5

11

Use the Button's PostBackUrl property. http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.button.postbackurl.aspx

<%@ page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="head1" runat="server">
  <title>Button.PostBackUrl Example</title>
</head>
<body>    
  <form id="form1" runat="server">

    <h3>Button.PostBackUrl Example</h3>

    Enter a value to post:
    <asp:textbox id="TextBox1" 
      runat="Server">
    </asp:textbox>

    <br /><br />

    <asp:button id="Button1" 
      text="Post back to this page"
      runat="Server">
    </asp:button>

    <br /><br />

    <asp:button id="Button2"
      text="Post value to another page" 
      postbackurl="Button.PostBackUrlPage2cs.aspx" 
      runat="Server">
    </asp:button>

  </form>
</body>
</html>
Chris Gessler
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    I saw that you are using 2 different buttons. Can it be done using a single button like `` – william Jun 22 '12 at 02:16
  • The first time around, don't fill in the PostBackUrl, fill it in during the first postback. Not sure on the form post, but regular postbacks should work fine with the JS code you have. – Chris Gessler Jun 22 '12 at 02:53
  • I just found out `PostBackUrl` only works for the pages within the same domain. But what my requirement is to post to another domain. Can it still be done with `PostBackURL` ? Tkz. – william Jun 22 '12 at 08:17
  • No. it will not post into another domain. You'll have to use the answer provided by @tcoder – Chris Gessler Jun 22 '12 at 13:21
2

This is one approach which I don't really recommend but it will do what you want. It uses javascript to change the url (e.g. to default2.aspx) the form is posted to using the form's action attribute and then repost the form

    protected void btnClick(object sender, EventArgs e)
    {
        string script = "<script> document.forms[0].action='default2.aspx'; document.forms[0].submit(); </script>";
        ClientScript.RegisterClientScriptBlock(this.GetType(), "postform", script);
    }

The second page should have EnableViewStateMac="false"

<%@ Page Language="C#" EnableViewStateMac="false" AutoEventWireup="true"
             CodeBehind="default2.aspx.cs" Inherits="CodeGen.default2" %>

Caution: Turn off MAC generation by setting enableViewStateMac=false in the page or web.config.. This isn't recommended, since the MAC helps prevent people from tampering with your viewstate data. But if tampering with viewstate data isn't a concern (& it may not be for some applications where there's no risk of fraud or security breaches), you can turn it off. Read More

codingbiz
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2

I had a similar issue. I had an asp:button which simply performed a postback. In the Page_Load IsPostBack portion, I did some complex validation. Most people just submit the form to the next page and do validation there, then redirect back if it fails. But I thought was was sloppy. So the solution was postback, then upon validation, submit from within the CodeBehind. I believe that's what you're looking for.

I'd like to draw this out with "detail", but it's very simple:

Server.Transfer("~/folder/page.aspx", True)

The "True" is a flag of whether or not to preserve the POST data. Works fine for me, let me know how it works for you.

http://www.codeproject.com/Articles/37539/Redirect-and-POST-in-ASP-NET

Suamere
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1

Similar issue. What a pain.

In the end I've put a form in the master page (this way it isn't inside another form):

<form method="post" id="asp-form-hack" style="display: none;"></form>

Then, in the aspx pages, I use it like this:

<script>
    $(document).ready(function () {
        var $loginButton = $("#login-button");
        var loginForm = document.forms["asp-form-hack"];
        loginForm.action = "<page-to-postback>.aspx";
        $loginButton.on("click", Login);

        function Login() {
            // read values from input fields in the page
            var username = $("#t_username").val();
            var password = $("#t_password").val();

            // create input elements with the same values
            var usernameInput = document.createElement("input");
            usernameInput.name = "txtUsername";
            usernameInput.type = "text";
            usernameInput.value = username;
            var passwordInput = document.createElement("input");
            passwordInput.name = "txtPassword";
            passwordInput.type = "password";
            passwordInput.value = password;

            // append the input elements to the form
            loginForm.appendChild(usernameInput);
            loginForm.appendChild(passwordInput);

            // setTimeout prevents your page from understanding
            // that you are submitting from another form
            setTimeout(function () {
                loginForm.submit();
            }, 0);
        }
    });
</script>

Please note that this method allows posting to other domains

user6307854
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-3

In code behind just use 

Response.Redirect("YourOtherPage.aspx?param1=xxx")
fenix2222
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