C / C++ / MFC

9-Aug-06 5:13

Hi,

I'm using an active-x control to browse some web pages and part of what I need to do involves not letting it spawn IE windows if a link happens to want to navigate outside of my own browser window. I was finally able to use NewWindow2 to prevent it from spawning new windows, however it did not return the URL the link would have gone to, so I found that NewWindow3 could handle that. Per the docs (http://msdn.microsoft.com/workshop/browser/webbrowser/reference/ifaces/dwebbrowserevents2/newwindow3.asp) there is a BSTR flag that holds the URL of the link that is supposed to be opening. However when I capture the URL I am only getting a line of question marks (like ?????????????????????????????????) instead of the URL I need.

Can someone assist in figuring out how to use NewWindow3 so I can capture the proper URL of the link I click on?

Thanks in advance!

David Crow9-Aug-06 5:58

9-Aug-06 5:58

univega_r304 wrote:
However when I capture the URL I am only getting a line of question marks (like ?????????????????????????????????) instead of the URL I need.

In a variable, or in the debug window?

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 6:04

9-Aug-06 6:04

In a variable. This is the code I am using to test....

void CLoadWebSite::OnNewWindow3(LPDISPATCH FAR* ppDisp, BOOL FAR* Cancel, BSTR Flags, BSTR URLContext, BSTR URL)
{
// Convert BSTR to CSTring
CString url = "";
VARIANT vnt;
vnt.bstrVal = URL;
url = vnt.bstrVal;

*Cancel = TRUE; // Prevent IE spawning

AfxMessageBox(url); // display popup of url value.

Browser.Navigate(url,NULL,NULL,NULL,NULL); // navigate to url
}

I get the same value if cancel is set to true or false. If it's false, the IE window spawns to the proper link. Both ways the URL is not returned to my variable, it just appears as all question marks.

David Crow9-Aug-06 6:51

9-Aug-06 6:51

univega_r304 wrote:
VARIANT vnt;

You need to set the vt member to VT_BSTR.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 7:03

9-Aug-06 7:03

Didn't seem to make any difference.. Here is my updated code (I hope I made the change you recommended correctly...):

ON_EVENT(CLoadWebSite, IDC_EXPLORER, 273 /* NewWindow3 */, OnNewWindow3Explorer1, VTS_DISPATCH VTS_PBOOL VTS_BSTR VTS_BSTR VTS_BSTR)

void CLoadWebSite::OnNewWindow3Explorer1(LPDISPATCH FAR* ppDisp, BOOL FAR* Cancel, BSTR *Flags, BSTR *URLContext, BSTR *URL)
{
CString url = "";
VARIANT vnt;
vnt.vt = VT_BSTR;
vnt.pbstrVal = URL;
url = vnt.bstrVal;

*Cancel = TRUE;
AfxMessageBox(url);

// Browser.Navigate(url,NULL,NULL,NULL,NULL);
}

David Crow9-Aug-06 7:11

9-Aug-06 7:11

univega_r304 wrote:
void CLoadWebSite::OnNewWindow3Explorer1(LPDISPATCH FAR* ppDisp, BOOL FAR* Cancel, BSTR *Flags, BSTR *URLContext, BSTR *URL)

I made an error. The last three parameters are indeed pass-by-value, not pass-by-reference. You can remove the '*' from them.

You should be able to set a breakpoint on the first statement in OnNewWindow3Explorer1() and see the value of URL. If it's not correct then, nor shall it be when assigned to url.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 7:26

9-Aug-06 7:26

Ok, I set it back to pass-by-value (I caught your earlier post you had deleted)

I set up a breakpoint on the line: url = vnt.bstrVal; and it shows me the URL! But why then is it displaying in AfxMessageBox as all ? marks.... hmmmm....

Paul Groetzner9-Aug-06 7:32

9-Aug-06 7:32

This is what I see in the debugger (Autos tab):

url tree ->

Name: url
Value: {...}
Type: ATL::CStringT<char,strtraitmfc<char,atl::chtraitscrt<char> > >

Name: ATL::CSimpleStringT<char,0>
Value: "*edited value* http://myinternallink"
Type: ATL::CSimpleStringT<char,0>

Name: m_pszData
Value: 0x6aed22a7 <bad ptr="">
Type: char *

Name: <warning symbol="">
Value: CXX0030: Error: expression cannot be evaluated

David Crow9-Aug-06 8:20

9-Aug-06 8:20

None of the vnt stuff is necessary. Just use:

CString url(V_BSTR(&URL));
AfxMessageBox(url);

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 8:31

9-Aug-06 8:31

That didn't work. The compiler didn't like it one bit Frown | :(

error C2227: left of '->bstrVal' must point to class/struct/union/generic type
type is 'BSTR *'

David Crow9-Aug-06 8:41

9-Aug-06 8:41

Show me your code once more. Did you try it with/out the ampersand?

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 9:04

9-Aug-06 9:04

Tried it with and without the ampersand. Pretty much the same error:

with:
error C2227: left of '->bstrVal' must point to class/struct/union/generic type
type is 'BSTR *'

without:
error C2227: left of '->bstrVal' must point to class/struct/union/generic type
type is 'BSTR'

Here's my code:

ON_EVENT(CLoadWebSite, IDC_EXPLORER, 273 /* NewWindow3 */, OnNewWindow3Explorer1, VTS_DISPATCH VTS_PBOOL VTS_BSTR VTS_BSTR VTS_BSTR)

void CLoadWebSite::OnNewWindow3Explorer1(LPDISPATCH FAR* ppDisp, BOOL FAR* Cancel, BSTR Flags, BSTR URLContext, BSTR URL)
{
CString url(V_BSTR(URL));
AfxMessageBox(url);

*Cancel = TRUE;

// Browser.Navigate(url,NULL,NULL,NULL,NULL);
}

David Crow9-Aug-06 9:57

9-Aug-06 9:57

I messed up (again). Blush | :O

Since URL is already a BSTR, as opposed to a VARIANT, it obviously cannot be run through the V_BSTR() macro.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 10:29

9-Aug-06 10:29

I've tried converting the value to CString every which way and it always comes to the same results no matter what, a line of several dozen ? marks.

This is getting quite frustrating Cry | :((

I have to assume then that it may be a problem with BSTR URL not reporting a proper url.

To test the NewWindow3 function I had my default site go to google.com, I searched on a something irrelevant and right-clicked to Open to a new window to trigger the event. In the debugger URL always comes back as a bunch of square shapes (I think because debugger can't display BSTR?, at least there's a doc somewhere on codeproject that said it couldn't, but it might have been for an older version of VS) and converting always results in ? marks...

If you want to test this you can do do very easily by going to this link:
http://www.codeproject.com/com/webbrowser.asp[^]

This is basically something similar to what I have. Just edit the code, change the default site if you wish and add the event for the NewWindow3 compile and have at it to see what you can find...

David Crow9-Aug-06 11:16

9-Aug-06 11:16

univega_r304 wrote:
I think because debugger can't display BSTR

It might indeed be a Unicode thing. This is the default for VS2003 and VS2005, but not so with VS6 (what I'm using).

In the Watch window, the symbol for strings is s while the symbol for Unicode strings is su. See here for more.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner9-Aug-06 17:57

9-Aug-06 17:57

Yeah, I'm using VS2005...

Here's a new bit a code that came very close...

void CLoadWebSite::OnNewWindow3Explorer1(LPDISPATCH FAR* ppDisp, BOOL FAR* Cancel, BSTR Flags, BSTR URLContext, BSTR URL)
{
BSTR b = URL;
_bstr_t orig(b);
CString cstring((char *)orig);
AfxMessageBox(_T(cstring));

*Cancel = TRUE;

Browser.Navigate(cstring,NULL,NULL,NULL,NULL);
}

When I debug this code the value for cstring is the URL I need! However, when I try to view it with AfxMessageBox or Navigate to it, it still thinks the value is all question marks.... I don't understand why it could show me one thing and do another... I wish there was a way to post a screenshot....

Any ideas?

David Crow10-Aug-06 3:30

10-Aug-06 3:30

univega_r304 wrote:
AfxMessageBox(_T(cstring));

The _T() macro is for string literals.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

David Crow10-Aug-06 5:09

10-Aug-06 5:09

univega_r304 wrote:

If you want to test this you can do do very easily by going to this link:
http://www.codeproject.com/com/webbrowser.asp[^]

This is basically something similar to what I have. Just edit the code, change the default site if you wish and add the event for the NewWindow3 compile and have at it to see what you can find...

I already had an application that uses this control, but for some reason it does not support the NewWindow3 event. What version of shdocvw.dll do you have? Mine is 6.0.2900.2937.

"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank

"Judge not by the eye but by the heart." - Native American Proverb

Paul Groetzner10-Aug-06 19:22

10-Aug-06 19:22

Unless it's on mulitple locations on my drive the version I have appears to be older... I have 6.0.2900.2919. According to the article on MSDN: NewWindow3 is available only in Microsoft Windows XP Service Pack 2 (SP2) or later. So if you have that, it should work...

FYI, after messing around a bit and not getting anywhere I put the code back that was showing me the proper URL in the debugger stopped working again. Same code, but bad results. I have't been able to get it to reproduce the proper URL in the debugger since. Mad | :mad:

Paul Groetzner11-Aug-06 9:17