how to get/trace asp.net outgoing response text

问题:

my server seems to be sometimes returning wrong html to webclients

im using asp.net 4 with VS 2012. debugging on IIS Express.

in order to debug this issue, id like to trace the html that asp.net is sending

in the Global_asax_PreRequestHandlerExecute i can access the response code and status, but cant seem to find the body html

i tried to read the OutputStream like this:

Dim ms = New MemoryStream
CurContext.Response.OutputStream.CopyTo(ms)
Dim sr = New StreamReader(ms)
Dim rtext = sr.ReadToEnd

but that throws a NotSupportedException Stream does not support reading.

any ideas?

thanks a lot

EDIT

i now tested this for sure

i have a label on the page with the following attributes

<asp:label id="l" runat="server" Font-Bold="true" Font-Size="X-Large" BackColor="Pink"/>

when displayed in the browser it shows just fine, as follows:

<span id="C1_FormView1_l" style="background-color:Pink;font-size:X-Large;font-weight:bold;">Processed</span>

but when downloaded with webclient i get

<span id="C1_FormView1_l"><b><font size="6">Processed</font></b></span>

why is the backcolor lost? and btw, why doesn't it use the more modern style attribute instead of adding b and font

if i could read the ResponseStream i would at least know WHERE it gets lost, even that i dont know now.

thank you very much

P.S. if .net 4.5 is better for this, then i might consider changing the target framework

回答1:

You can get the HTML (and modify it) by overriding Render on the page / site master.

        protected override void Render(System.Web.UI.HtmlTextWriter writer)
        {
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
            {
                using (System.IO.StreamWriter sw = new System.IO.StreamWriter(ms))
                {
                    HtmlTextWriter tw = new HtmlTextWriter(sw);
                    base.Render(tw);
                    tw.Flush();
                    ms.Position = 0;
                    using (System.IO.StreamReader sr = new System.IO.StreamReader(ms))
                    {
                        string yourHTML = sr.ReadToEnd();
                        // do stuff with yourHTML
                        Response.Write(yourHTML);
                        sr.Close();
                        tw.Dispose();
                    }
                }
            }
        }

in vb

Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
        Using ms As New System.IO.MemoryStream()
            Using sw As New System.IO.StreamWriter(ms)
                Dim tw As HtmlTextWriter = New HtmlTextWriter(sw)
                MyBase.Render(tw)
                tw.Flush()
                ms.Position = 0
                Using sr As New System.IO.StreamReader(ms)
                    Dim yourHTML As String = sr.ReadToEnd()
                    'do stuff with yourHTML'
                    Response.Write(yourHTML)
                    sr.Close()
                    tw.Dispose()

                End Using
            End Using
        End Using
    End Sub

回答2:

this does not answer my original question technically, but it does solve the issue i was having

the problem was that the html wasnt rendering correctly

i now remembered that aspx has adaptive rendering, so i fgured the useragent used in the request might be to blame

i changed my code to:

 Dim myReq As HttpWebRequest = WebRequest.Create(MailUrl)
 myReq.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.89 Safari/537.1"
 Dim resp As HttpWebResponse = myReq.GetResponse
 Dim stream = resp.GetResponseStream
 Dim rdr = New StreamReader(stream)
 Dim BodyText = rdr.ReadToEnd

and now the html is rendering in correct modern Html5/Css3 markup

i appreciate your help and guidance.