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Tom
Guest
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 Posted: Sun Feb 18, 2007 7:22 pm Post subject: TCPPWebBrowser causing an AV |
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Any reason the code below would cause the application to
have an AV when the application is closed? It only occurs when
the movie is played at all. If the play button isn't pressed,
no error.
Place a TCPPWebBrowser on a form and this in the constructor
to reproduce.
AnsiString HTML = "\
<html><body bgcolor=#8ca9c6>\
<table width=95% border=0 align=center bgcolor=#000000
style='font-size:14px'>\
<tr bgcolor=#FFFFFF><td style='padding:5px;text-align:center;'><object
width=\"425\" height=\"350\"><param name=\"movie\"
value=\"http://www.youtube.com/v/MEIWM91WZTA\"></param><param name=\"wmode\"
value=\"transparent\"></param><embed
src=\"http://www.youtube.com/v/MEIWM91WZTA\"
type=\"application/x-shockwave-flash\" wmode=\"transparent\" width=\"425\"
height=\"350\"></embed></object></td></tr>\
</table>\
</body></html>";
this->CppWebBrowser1->Navigate(L"about:blank");
while(this->CppWebBrowser1->Busy)
Application->ProcessMessages();
TMemoryStream* mstm=new TMemoryStream();
mstm->Write(HTML.c_str(), HTML.Length());
mstm->Seek(0, soFromBeginning);
IPersistStreamInit* pPersistStreamInit = NULL;
TStreamAdapter *IStr=new TStreamAdapter(mstm,soReference);
this->CppWebBrowser1->Document->QueryInterface(IID_IPersistStreamInit,(void**)&pPersistStreamInit);
pPersistStreamInit->Load(*IStr);
pPersistStreamInit->Release();
pPersistStreamInit=NULL;
delete mstm;
Thanks,
Tom |
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Remy Lebeau (TeamB)
Guest
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| Posted: Wed Feb 21, 2007 12:52 am Post subject: Re: TCPPWebBrowser causing an AV |
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"Tom" <tom (AT) nospam (DOT) net> wrote in message
news:45d852e5$1 (AT) newsgroups (DOT) borland.com...
| Quote: | while(this->CppWebBrowser1->Busy)
Application->ProcessMessages();
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You need to use the ReadyState property instead of the Busy property
while(this->CppWebBrowser1->ReadyState != READYSTATE_COMPLETE)
Application->ProcessMessages();
A safer and better approach would be to use the OnNavigateComplete
event instead.
| Quote: | TStreamAdapter *IStr=new TStreamAdapter(mstm,soReference);
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You are not freeing the TStreamAdapter anywhere.
Gambit |
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Tom
Guest
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| Posted: Wed Feb 21, 2007 3:11 am Post subject: Re: TCPPWebBrowser causing an AV |
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| Quote: | You are not freeing the TStreamAdapter anywhere.
I tried simply deleting it and that didn't work. So I used |
Adapter->_Release();
Adapter = NULL;
Is that correct?
With that in place it still causes an access violation
when the application is closed.
Thanks,
Tom |
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Eduardo Jauch
Guest
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| Posted: Wed Feb 21, 2007 4:18 am Post subject: Re: TCPPWebBrowser causing an AV |
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In yor code, you used this form to acess the TCppWebBrowser:
this->CppWebBrowser1->...
Your code don't show, but the pointer "this" is unecessary, unless you
have another variable named "CppWebBrowser1" :)
Tom escreveu:
| Quote: | You are not freeing the TStreamAdapter anywhere.
I tried simply deleting it and that didn't work. So I used
Adapter->_Release();
Adapter = NULL;
Is that correct?
Where is "Adapter" in your code? |
| Quote: | With that in place it still causes an access violation
when the application is closed.
|
TStreamAdapter *IStr=new TStreamAdapter(mstm,soReference);
This MUST be freed with "delete", because you used the operator "new".
I think that are objects that can free itself, etc, but this don't seens
the case...
So, use:
delete IStr;
For the access violation, if it continues after you delete IStr, so the
problem problably are on another portion of your program... ;)
Sometimes this can happen when you try to delete an object previously
deleted... Or you are trying to access an empty object...
Take a look on the rest of your code... :)
If this is the ONLY piece of code... Well... I can't figure what is
wrong but the ausence of delete IStr... |
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Tom
Guest
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| Posted: Wed Feb 21, 2007 7:41 am Post subject: Re: TCPPWebBrowser causing an AV |
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Thanks Eduardo,
However, as I stated (though I didn't state why), delete IStr fails. It
actually causes another access violation, which is why I went to releasing
and nulling it.
That is the only piece of code in the entire application, so the problem is
there.
Also, the this-> point is there because the code was copied out of another
project where it is required.
Regards,
Tom |
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Eduardo Jauch
Guest
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| Posted: Wed Feb 21, 2007 9:10 am Post subject: Re: TCPPWebBrowser causing an AV |
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Tom escreveu:
| Quote: | Thanks Eduardo,
However, as I stated (though I didn't state why), delete IStr fails. It
actually causes another access violation, which is why I went to releasing
and nulling it.
|
I tested the code with the suggestion of Remy.
while(this->CppWebBrowser1->ReadyState != 4)
Application->ProcessMessages();
Got an error because ambiguity with READYSTATE_COMPLETE, so i used
insted the number 4 (value on the help).
I try to put delete IStr. Fails like you said.
| Quote: | Also, the this-> point is there because the code was copied out of another
project where it is required.
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Unfortunate the "this" is the problem. Without the this->, the error
when you close the application without play the video don't happen. :)
I don't have any idea WHY... ^-
But it's very interesting...
Same for why "delete IStr" don't work...
But I know that the delete don't work because this line:
pPersistStreamInit->Load(*IStr);
Without this, the delete works properly...  The program no, of corse  |
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José
Guest
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| Posted: Thu Mar 08, 2007 8:56 pm Post subject: Re: TCPPWebBrowser causing an AV |
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On Sun, 18 Feb 2007 07:22:15 -0600, "Tom" <tom (AT) nospam (DOT) net> wrote in
borland.public.cppbuilder.internet.web:
| Quote: | Place a TCPPWebBrowser on a form and this in the constructor
to reproduce.
|
What is a TCPPWebBrowser ?
--
José |
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Remy Lebeau (TeamB)
Guest
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| Posted: Fri Mar 09, 2007 12:10 am Post subject: Re: TCPPWebBrowser causing an AV |
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"José" <jose (AT) 127 (DOT) 0.0.1> wrote in message
news:us80v2984npdl9o33so1kssfpalfp99ol6 (AT) 4ax (DOT) com...
| Quote: | What is a TCPPWebBrowser ?
|
TCppWebBrowser is a VCL component that ships with BCB. It is a
wrapper for the Internet Explorer ActiveX control, which allows IE to
be embedded in applications.
Gambit |
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José
Guest
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| Posted: Fri Mar 09, 2007 2:29 am Post subject: Re: TCPPWebBrowser causing an AV |
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On Thu, 8 Mar 2007 10:10:06 -0800, "Remy Lebeau \(TeamB\)"
<no.spam (AT) no (DOT) spam.com> wrote in borland.public.cppbuilder.internet.web:
| Quote: | What is a TCPPWebBrowser ?
TCppWebBrowser is a VCL component that ships with BCB. It is a
wrapper for the Internet Explorer ActiveX control, which allows IE to
be embedded in applications.
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Can I obtain it for use in CPP Builder?
--
José |
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Remy Lebeau (TeamB)
Guest
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| Posted: Fri Mar 09, 2007 2:31 am Post subject: Re: TCPPWebBrowser causing an AV |
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"José" <jose (AT) 127 (DOT) 0.0.1> wrote in message
news:5gs0v21m01eaams9skiiau5h78h8m3aarf (AT) 4ax (DOT) com...
| Quote: | Can I obtain it for use in CPP Builder?
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Like I said, it already ships with BCB. It is on the "Internet" tab
of the Component Palette.
Gambit |
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