ASP.net c# post form on users behalf

Question

I have an ASP button, when it is clicked it calls a function which adds order information into my database. The next step of the order process is to transfer the user over to the payment gateway with this form:

<form action="https://select-test.wp3.rbsworldpay.com/wcc/purchase" name="BuyForm" method="POST">
<input type="hidden" name="instId"  value="151711">
<input type="hidden" name="cartId" value="abc123">
<input type="hidden" name="currency" value="GBP">
<input type="hidden" name="amount"  value="1221">
<input type="hidden" name="desc" value="">
<input type="hidden" name="testMode" value="100">
<input type="submit" value="To Payment!">
</form>

However I really would like it so that the user:

Pressed order button -> Order function called -> User automatically passed to order page

As supposed to:

Pressed order button -> Order function called -> User goes to another page -> User manually clicks button to go to worldpay payment page

Is there anyway in c# to redirect the user to the order page, and submit form data with them?

Answer 1

You can use Response.Redirect("OtherPage.aspx"); at the end of your event handler. Using this method, you could append items to the query string (for example the order ID)... Response.Redirect("OtherPage.aspx?OrderID=abcdef");.

Alternatively, you could do the processing in the order page and list it as the PostbackUrl, so the first page posts back directly to the order page.

Answer 2

Multiple ways:

1) Put the order in Session state and carry it along with the user, automatically retrieving it when they are redirected to the final page.

2) Create a form which submits its data with the new page as the target (rather than posting back to itself as the default behavior in ASP.Net).

3) Generate a form with hidden fields and output it to the page.

In situations #2 and #3, you might choose to use client-side script to automatically submit the form.