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Hi EveryOne,
I have added a class which contains a method that accepts a VARIANT type variable in an ActivexDll written in VC++. In one of sample code I found the a value is assigned to the VARIANT type variable using a SAFEARRAY. My question is how can a string value be assigned to VARIANT type variable(type casting in strcpy does't work). Can we achieve it only by using SAFEARRAY? if yes why is it so? Is there any other way to obtain the same? kindly explain. Thank you.
Regards,
LG.
lgatcodeproject
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Probably you should use a BSTR insted.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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Hi,
Even if I use the BSTR type while copying a string constant using strcpy with a type cast the application crashes. How to copy a string constant by-passing this problem?
Please find the below snippet.
<br />
STDMETHODIMP CRAPClientX::Connect(BSTR serverIP, BSTR serverPort,BSTR output)<br />
{<br />
strcpy((char *)output, "connected");<br />
return S_OK;<br />
}<br />
Regards,
LG.
lgatcodeproject
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lgatcodeproject wrote: STDMETHODIMP CRAPClientX::Connect(BSTR serverIP, BSTR serverPort,BSTR output)
{
// TODO: Add your implementation code here
strcpy((char *)output, "connected");
return S_OK;
}
Change to
STDMETHODIMP CRAPClientX::Connect(BSTR serverIP, BSTR serverPort,BSTR * pOutput)
{
*pOutput = SysAllocString(L"connected");
return S_OK;
}
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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Hi,
Thanks its working now but then I have a doubt, what is that L do inside SysAllocString()function.
Regards,
LG.
lgatcodeproject
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A BSTR is substantially a wide char string (technically it is a OLECHAR one). the L prefix creates a wide char literal.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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There are too many string types you can use in your VC++ project.
STL and many other non-MS libs use string class; MFC prefers CString; when it comes to COM, you will see _bstr_t and BSTR. ……
Many code in my project just do string conversions——convert from one string type to another, which makes me fell ugly.
Hello everyone, which is your favorite string type? 
A Chinese VC++ programmer
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I mainly use STL string unless I have to use CString for when working with MFC. Never did any COM programing so never used _bstr_t or BSTR.
-Saurabh
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STL's basic_string template class is much more flexible in this respect and allows you to create any kind of the strings suitable for specific scenarios.
You can use CString if the size of the project is going to be small. In case the project is a large one than I would rather prefer a wrapper class to encapsulate all the functionality and use it.
BSTR's are used in COM.It's better to convert the CString to a _bstr_t and then pass it to the COM interface if you are working with COM since they have to maintain compatibility with VB datatypes and components can be invoked from there.
Somethings seem HARD to do, until we know how to do them.
 _AnShUmAn_
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Thank you! Your suggestion is very constructive.
I do like STL's basic_string, but I have to use its c_str() memfunc when I pass a string object to MFC classes. 
A Chinese VC++ programmer
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TCHAR*
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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I believe you're not serious 
A Chinese VC++ programmer
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You're wrong.
(Well, I often have to use one or more of the classes you were talking about, but usually I prefer going to the metal)
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
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I know what you're mean.
Thank you!
A Chinese VC++ programmer
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Ozer Karaagac wrote: Maybe, you may want to consider this.
No. That is so old and ugly stuff. Most of it is even for VC6!
And look at the second picture (the one named "Screenshots of native C++ equivalent") and how his class MLFString has a equals()-member!  
Somone who programs JAVA in C++ is not someone to whose programming tip I tend to listen!
Let's think the unthinkable, let's do the undoable, let's prepare to grapple with the ineffable itself, and see if we may not eff it after all.
Douglas Adams, "Dirk Gently's Holistic Detective Agency"
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Three negative votes against just sharing an article without revealing any acceptance.
Isn't it somewhat harsh? What a great liking to vote negative?
Is this STL fanaticism? If so, good luck to you with your lovely STL.
In STL we trust. 
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I don't really like any of them, but use whatever fits best into the current project. For instance, now I work on something with lots of COM, so I use CComBSTR. On the previous job, we were making an OS-portable system, so the obvious choice was std::string.
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all depends.
i used to strongly abandon C-style strings (char* and all its variants) as long as i can. of course, when I have to use the C runtime (or any C APIs), then it's the only really valid reason to...
as long as I code in C++, I use C++ strings.
I used to use the MVC pattern also. so, for my UI layer, I mainly use CString as I use MFC.
but as for my other layers (which are generally put into DLLs), i use std::string
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Hi!
I'm Rathakrishnan. I've to create a ToolBar(like Google ToolBar) for a site using C++. Is there any Articles for this? Any body can help?
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Click here [^]
Yes U Can ...If U Can ,Dream it , U can do it ...ICAN
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Hello all,
I am having problem with HtmlView class. I am using this class to load web page from any URL. But the url, i am apecifying contains character SWf in url string. So is it possible that URL is not being able to load because of SWF word. Other sites that contains flash content are being loaded then why problem is created for below URl?
http://www.webkinz.com/SWF/setLocale.swf?locale=us_en
[^]
Any help is highly appreciated.
Thanks & Regards
Hemang
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Have you tried with IE, HtmlView is based WebBrowserCtrl which is used in IE.
This site is blocked in my office PC and says it comes in Games Category may be the similar reason.
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What is the reason? This is being able to open in IE7. Then why is it not being open in my application?
Thanks & Regards,
HEmang
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