HTTP headers and Response.Redirect

[Sam]

I have some issues with HTTP Headers and I was hoping for
some pointers or references to good articles.

Here is the problem.
I have 6 .aspx pages, each page contains a common .ascx.
This ascx serves two purposes, 1. it contains a tab strip
with response.redirects to navigate to the other pages;
2. I authenticate the user by check to see if a cookie
exists, if it doesn't I redirect to a login screen.

Now recently when the user is redirected I receive error
messages such as "The object was aborted" and "Object
moved to here". From what I have read I am getting these
error messages because I have sent HTTP headers to the
client before I redirect. Apparently response.end raises
an exception, so I added false for the endResponse
property on the response.redirect, but that didn't fix
the problem.

So what actions send HTTP headers? Do any of the
following, which are contained in my pages?
1. Page.DataBind()
2. Context.Response.Cookies("name").Values("val") = ...
3. Page.RegisterClientScriptBlock("...")
4. Session.Item("name") = ...
5. Accessing a web control e.g. txtFirstname.text = "xxx"
(textbox)
6. Third Party server controls. Im using
Coalesys.WebMenu for dropdowns.

Is there a tracing tool to see if headers have been sent?

Any assistance would be greatly appreciated.
Sam

 

[Rick Strahl [MVP]]

Hi Sam,

The easiest thing to do might be to just call Response.Clear() before you
call Response.Redirect(). I actually thought this happened automatically,
but apparently not...

+++ Rick ---

--

Rick Strahl
West Wind Technologies
http://www.west-wind.com/
http://www.west-wind.com/wwHelp

 

[sam]

Hi Rick,
I tried that but I still randomly get "Object moved to
here". Will I have to set buffering properties for this
to work. IIS has "Enable Buffering" ticked and each .aspx
page has buffer set to true.

Sam

 

[Rick Strahl [MVP]]

Remember one thing: Redirects don't send any headers, so if you are setting
cookies (or use a Session object for the first time) the redirect will loose
the cookie/session/header since it's not being sent.

+++ Rick ---

--

Rick Strahl
West Wind Technologies
http://www.west-wind.com/
http://www.west-wind.com/wwHelp