我如何使用Fiddlercore编辑HTTP请求C＃

Question

What I want to be able to do: Edit HTTP Requests before they are sent off to the server

User navigates to a webpage of their choice in their browser > They encounter a request they wish to edit > they edit the request and then that gets sent to the server instead of the original one.

What I have done so far: I have captured the request, now I need help finding the code to edit it. Here is my code for capturing the request so far:

    Fiddler.FiddlerApplication.BeforeRequest += sess =>
    {
        //Code to detect user specified URL here
    }

Is it possible for me to edit the request before it is actually sent? If it can be done using the FiddlerCore API only then I'd be grateful, although I am willing to download more binaries if required.

Additional notes: I have tried streamwriters, binary writers, copy the respose into a memory stream edit it then copy it back, none of those methods work for me. Also when I try some methods my app just hangs and doesn't respond to things like pressing the X.

Maybe I'm just bad at explaining what I'm trying to achieve seems the only good answer I have has been about reponses :/

If the request reads the string "hello world" then I'd like the user to be able to change the REQUEST to say "hello there"

Answer 1

Such a noobish mistake I made, I thought that RequestBody was read only! Turns out I could have simply edited the response like this:

    session.RequestBody = myBytes;

Really annoyed at myself for this!

Answer 2

In the demo app, adding the delegate is shown as:

    Fiddler.FiddlerApplication.BeforeResponse += delegate(Fiddler.Session oS) {
        // Console.WriteLine("{0}:HTTP {1} for {2}", oS.id, oS.responseCode, oS.fullUrl);

        // Uncomment the following two statements to decompress/unchunk the
        // HTTP response and subsequently modify any HTTP responses to replace 
        // instances of the word "Microsoft" with "Bayden". You MUST also
        // set bBufferResponse = true inside the beforeREQUEST method above.
        //
        //oS.utilDecodeResponse(); oS.utilReplaceInResponse("Microsoft", "Bayden");
    };