Is it possible to add an event handler for SHDocVw.WebBrowser or use AxSHDocVw.WebBroswer without a

[David]

I would like to use a AxSHDocVw.WebBroswer control in a Windows service- is
this possible without creating a form? I added the reference I usually use
to add this object in a Windows Application but only SHDocVw appears under
References in the Solution Explorer.

As an alternative, SHDocVw.WebBrowser may work but I am not sure how to add
an event handler for it- does anyone know how to add a DocCompleted event
for this object?

 

[Herfried K. Wagner [MVP]]

I would like to use a AxSHDocVw.WebBroswer control in a Windows service- is
this possible without creating a form? I added the reference I usually use
to add this object in a Windows Application but only SHDocVw appears under
References in the Solution Explorer.

I wonder why you would want to use a visual control in a service which
doesn't provide a user interface.

* What exactly do you want to archieve?
* Which version of .NET are you using?

 

[Cor Ligthert [MVP]]

David,

Not tested however maybe you can try it by using instead of x.webbrowser
x.InterNetExplorer that normaly opens the standard browser.

Cor

 

[David]

I wonder why you would want to use a visual control in a service which
doesn't provide a user interface.

* What exactly do you want to archieve?
* Which version of .NET are you using?

I'm writing a service that will connect to a website on a regular basis,
retrieve information, and then update external devices- this works fine as
an application but I would rather not use task scheduler to run it and a
service sounds like the best method for this. I started out using
HttpWebRequest but was not successful logging into the website with it-
axWebBrowser worked nicely.

I tried using the common component WebBrowser instead of the ActiveX one but
ran into problems accessing the DOM. I tried creating a HTMLDocument
variable and setting it equal to WebBrowser.Document but encountered a
"specified cast is not valid" error. Using the debugger to look at the
WebBrowser.Document property lead me to a "cannot obtain value" message- the
WebBrowser had loaded a webpage so I'm stuck there with that one, and stuck
with the event handler on SHDocVw.WebBrowser.

 

[Herfried K. Wagner [MVP]]

I'm writing a service that will connect to a website on a regular basis,
retrieve information, and then update external devices- this works fine as
an application but I would rather not use task scheduler to run it and a
service sounds like the best method for this. I started out using
HttpWebRequest but was not successful logging into the website with it-
axWebBrowser worked nicely.

Which authentication model does the Web site use?

Maybe this code snippet is of use for you:

<URL:http://dotnet.mvps.org/dotnet/code/net/#CookieRequest>

Otherwise take a look at the 'NetworkCredentials' class.

I would not use the webbrowser control for this purpose. Instead you can
download the file in the background:

<URL:http://dotnet.mvps.org/dotnet/code/net/#InternetLoadFile>

Parsing an HTML file:

MSHTML Reference
<URL:http://msdn.microsoft.com/library/default.asp?url=/workshop/browser/mshtml/reference/reference.asp>

- or -

..NET Html Agility Pack: How to use malformed HTML just like it was
well-formed XML...
<URL:http://blogs.msdn.com/smourier/archive/2003/06/04/8265.aspx>

Download:

<URL:http://www.codefluent.com/smourier/download/htmlagilitypack.zip>

- or -

SgmlReader 1.4
<URL:http://www.gotdotnet.com/Community/...mpleGuid=B90FDDCE-E60D-43F8-A5C4-C3BD760564BC>

If the file read is in XHTML format, you can use the classes contained in
the 'System.Xml' namespace for reading information from the file.

 

[David]

Maybe this code snippet is of use for you:

<URL:http://dotnet.mvps.org/dotnet/code/net/#CookieRequest>

Not sure what I'm doing wrong but I am having difficulties using WebClient.
No problems with HttpWebRequest but I am not sure how to access the DOM with
MSHtml...

This is what I'm trying with WebClient:

Dim Client As New WebClient()
Client.Headers.Add("Content-Type", "application/x-www-form-urlencoded")
Client.DownloadData("https://website...")
Client.Headers.Add("Cookie", Client.ResponseHeaders("Set-Cookie"))
Dim Data() As Byte = Client.UploadData("https://website...", "POST",
Encoding.UTF8.GetBytes("postdatahere"))
Dim thisstring As String
thisstring = Encoding.UTF8.GetString(Data)
Client.Dispose()
MsgBox(Encoding.UTF8.GetString(Data))

It seems as if the cookie isn't being retained properly, here is what works
for me using HttpWebRequest:

Dim myWebRequest As HttpWebRequest =
CType(WebRequest.Create(https://website...), HttpWebRequest)
Dim WebResponse As HttpWebResponse
Dim srReader As StreamReader
Dim swWriter As StreamWriter
Dim strPostData As String
Dim strResponse As String
Dim myMSHTML As mshtml.HTMLDocument
Dim myDoc As mshtml.IHTMLDocument2
myWebRequest.CookieContainer = New CookieContainer
WebResponse = myWebRequest.GetResponse
strPostData = "POST data"
myWebRequest = CType(WebRequest.Create(https://website...), HttpWebRequest)
myWebRequest.Method = "POST"
myWebRequest.ContentLength = strPostData.length
myWebRequest.ContentType = "Content-Type: application/x-www-form-urlencoded"
myWebRequest.CookieContainer = New CookieContainer
swWriter = New StreamWriter(myWebRequest.GetRequestStream)
swWriter.Write(strPostData)
swWriter.Close()
WebResponse = myWebRequest.GetResponse
srReader = New StreamReader(WebResponse.GetResponseStream)
strResponse = srReader.ReadToEnd
srReader.Close()

here's where i start to run into problems with HttpWebRequest though:

myDoc = New mshtml.HTMLDocument
myDoc.clear()
myDoc.write(strResponse)
myDoc.close()

 

[David]

After experimenting some more I found that the following is enough to do the
trick:


strPostData = "POST Data"
myWebRequest = CType(WebRequest.Create(https://website...), HttpWebRequest)
myWebRequest.Method = "POST"
myWebRequest.ContentLength = strPostData.length
myWebRequest.ContentType = "Content-Type: application/x-www-form-urlencoded"
myWebRequest.CookieContainer = New CookieContainer

If the CookieContainer is commented out things do not work. I guess I need
to figure out how to duplicate this with WebClient (or convert this response
to a MSHtml.Document).