Question

I recently started using the updated beta tools for Windows Phone 7 and ran into an interesting problem. It seems that with Fiddler running, any Http requests run through the emulator start returning a null result and create a “not found” web exception. This is easy to reproduce with WebClient.DownloadStringAsync(). The old versions of the emulator did work with Fiddler if I remember correctly. Has anyone had luck getting the two to work together? If it’s not possible I’d be open to any other tool that could help debug web requests from the WP7 emulator.

Answer 1

It looks like there is a blog post that describes getting fiddler working with Win Phone 7 through some customized rules for setting up Fiddler as a Reverse Proxy.

Here is a little bit of the instructions from the fiddler website, but the blog post seems a little clearer (sorry for wacky format, the block quote is not cooperating):

Option #1: Configure Fiddler as a
Reverse-Proxy Fiddler can be
configured so that any traffic sent to
http://127.0.0.1:8888 is automatically
sent to a different port on the same
machine. To set this configuration:

Start REGEDIT Create a new DWORD named
ReverseProxyForPort inside
HKCU\SOFTWARE\Microsoft\Fiddler

Set the DWORD to the local port you’d like
to re-route inbound traffic to
(generally port 80 for a standard HTTP
server) Restart Fiddler Navigate your
browser to http://127.0.0.1:8888

Option #2: Write a FiddlerScript rule
Alternatively, you can write a rule
that does the same thing.

Say you’re running a website on port
80 of a machine named WEBSERVER.
You’re connecting to the website using
Internet Explorer Mobile Edition on a
Windows SmartPhone device for which
you cannot configure the web proxy.
You want to capture the traffic from
the phone and the server’s response.

Start Fiddler on the WEBSERVER
machine, running on the default port
of 8888. Click Tools | Fiddler
Options, and ensure the “Allow remote
clients to connect” checkbox is
checked. Restart if needed. Choose
Rules | Customize Rules. Inside the
OnBeforeRequest handler, add a new
line of code: if
(oSession.host.toLowerCase() ==
“webserver:8888”) oSession.host =
“webserver:80”; On the SmartPhone,
navigate to http://webserver:8888
Requests from the SmartPhone will
appear in Fiddler. The requests are
forwarded from port 8888 to port 80
where the webserver is running. The
responses are sent back through
Fiddler to the SmartPhone, which has
no idea that the content originally
came from port 80.