ATL / WTL / STL

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BSTR returns invalid characters when multiple event sinks are used Aby Philip28-Jun-04 20:06 Aby Philip 28-Jun-04 20:06  Hi I have a component implementing a proprietary protocol (say, Protocol.dll)and does the communciation over serial port. I have defined ATL objects for each type of packet, and nearly all has a property called "description" which returns a BSTR. One ATL object encapsulates the serial communication. So I can set the baud rate, port number etc. A connection point event is defined corresponding to each packet that may arrive to the PC (from the device). Say ProtocolPkt1, ProtocolPkt2, ProtocolPkt3 etc. Now we typically use 2 serial ports. One that does proper protocol communciation and another that dumps trace staements. To take care of the trace statements I have one event defined (LogData) in the same event interface described above. I have an application (say Mainwindow.exe) that uses the above component, connects to both the ports and has separate event sinks to handle the 2 ports separately. The protocol data and the log data coming from the 2 ports are to be shown in separate windows. Whenever an event notifies that log data is received it is simply dumped in a window. Whenever any event notifying any of the protocol packets is received, the corresponding packet is created from the bytes received in the event, interpreted and displayed. Now onto the problem. When some protocol packets are received, the description property has to be called. When both the ports are connected the log data comes fine. But when the description property of say ProtocolPkt1 event is called, the BSTR returned is prefixed with some log string that came in the LogData event. Further the application displays a crash when it is closed. Some more observations. 1. This does not happen when the BSTR returned is very short. Typically only when the string returned is long and computed in some for loop, does this corruption occur. 2. This does not happen when I use the debug version of Protocol.dll. I hope I have made myself clear. If any information is required please let me know. Any pointers that can help me proceed would be greatly appreaciated Thanks aby Re: BSTR returns invalid characters when multiple event sinks are used palbano29-Jun-04 13:53 palbano 29-Jun-04 13:53  >> 2. This does not happen when I use the debug version of Protocol.dll. Have you tried looking at this article Surviving the Release Version? "No matter where you go, there your are." - Buckaroo Banzai -pete Re: BSTR returns invalid characters when multiple event sinks are used vprashu1-Jul-04 9:05 vprashu 1-Jul-04 9:05  Make sure that the code that fires the event manages the life time of the BSTR. I suspect that the first client is releasing the BSTR and hence ur second client sees garbage. For events and BSTR the caller allocates and frees the bstr. if u are using _bstr_t always pass a copy to the event( bstrVar.copy()) Hope this helps.. prashu Re: BSTR returns invalid characters when multiple event sinks are used Jörgen Sigvardsson1-Jul-04 11:31 Jörgen Sigvardsson 1-Jul-04 11:31  Hmm.. never send a copy of a BSTR to a COM method. That means that the method is responsible for cleaning up the string. This however is against COM rules, as [in] parameters MUST be managed by the caller. If the string has to be marshalled through the method call, then the string passed in will be lost (memory leak), and the callee will free a bstr which it does not own (the marshaller owns it). Thus, if you are using a _bstr_t or a CComBSTR, pass the BSTR pointer (or adress of if passing as an [out] argument) managed by these classes. [in] parameters are managed by called [out] parameters are allocated by callee, and passed for ownership to caller -- Ich bin Joachim von Hassel, und ich bin Pilot der Bundeswehr. Welle: Erdball - F104-G Starfighter Web browser controls in vs.net Ram. Sundar28-Jun-04 6:23 Ram. Sundar 28-Jun-04 6:23  Hi! I recently upgraded from VC 6.0 to VS.net 2002. I am using WTL v7.0. I created a simple modal dialog application and added a web browser control to it. The compilation was successful but the application refuses to create a dialog. Can anyone tell me what I should do to get my app up and running? After this happened, I created a similar project in VC 6.0 and it seems to work well there. When I open the same project (that I created in VC 6.0) in vs.net 2002 and convert it to VC 7.0 project and compile it, I get a problem hRes = _Module.Init(NULL, hInstance); I replaced this piece of code with hRes = _Module.Init(NULL, hInstance, &LIBID_ATLLib); I presume this is because of some ATL incompatibility?! Can anyone please help me with this? Thanks! Ram How to debug asp component? wood27-Jun-04 23:25 wood 27-Jun-04 23:25  Hi,erveryone, I don't know how to debug my asp component,Can you help me ?Thanks! Re: How to debug asp component? Jaime Stuardo30-Jun-04 5:58 Jaime Stuardo 30-Jun-04 5:58  You need to register the DLL in MTS or Component Services first. I will assume you are in Windows 2000/XP so I'll refer to those. Using MTS, the procedure is analogous. 1.- In Component Services, right click on the Application containing your component. Click properties. 2.- Copy the Application ID to clipboard 3.- In Visual C++ with your component project opened. Go to Project Settings. 4.- Be sure it is selected Debug configuration. Go to Debug Tab. 5.- Under "Executable for debug session:" write: C:\WINNT\system32\DLLHOST.EXE (obviously the path should be the path where DLLHOST.EXE file is in your system) 6.- Under "Program arguments:" write: /ProcessId:{the application ID you previously copied to clipboard} 7.- Now place a breakpoint where you want to start debugging 8.- Run the component (you will be warned that DLLHOST.EXE doesn't have debug information... just click OK) 9.- Run your ASP Page. When the breakpoint is reached, Visual C++ IDE will be activated for you to continue debugging your component as any Visual C++ program. 10.- If you make changes to your component, you may need to shutdown the component services Application before you can debug it again. I hope this helps Jaime Exceptions raised while CoCreateInstance Anonymous24-Jun-04 23:46 Anonymous 24-Jun-04 23:46  Hi, I am developing multithreading COM EXE server. In one of the methods I have called CoCreateInstance, which is made threadsafe by using CSingleLock(&(oneMutext)). After some time of server starts, this CoCreateInstance raises an exception. Also heap get corrupted at this instance. Can anybody help me in resolving this issue. Mandar Where can I find WTL reference? Ajnstajn23-Jun-04 0:15 Ajnstajn 23-Jun-04 0:15  Where can I find WTL reference to download it, including explanations of every member functions and variables for every class? Fore Thanks Ajnstajn Re: Where can I find WTL reference? palbano23-Jun-04 5:30 palbano 23-Jun-04 5:30  Does not exist. CodeProject may have the best collection of WTL stuff available. Search Articles for WTL. -pete Re: Where can I find WTL reference? Michael Dunn23-Jun-04 14:16 Michael Dunn 23-Jun-04 14:16  There is The WTL Documentation Project[^] which is just Doxygen-generated web pages, not explanations of the various classes/methods. I have a series of tutorials (starting here[^]) on using WTL. Check them out, they may be more helpful in getting you up and running with using WTL. --Mike-- Personal stuff:: Ericahist | Homepage Shareware stuff:: 1ClickPicGrabber | RightClick-Encrypt CP stuff:: CP SearchBar v2.0.2 | C++ Forum FAQ ---- Pinky, are you pondering what I'm pondering? I think so Brain, but if we shaved our heads, we'd look like weasels! Re: Can't get C++ ATL example to work...help? *Dreamz23-Jun-04 5:03 *Dreamz 23-Jun-04 5:03  I think m_spBrowser is in CScanCtl. Debugging CoTaskMemAlloc LasVegasGuy22-Jun-04 10:10 LasVegasGuy 22-Jun-04 10:10  Is there a way in ATL to debug CoTaskMemAlloc/Realloc calls and make sure that CoTaskMemFree was called for every allocation? thanks Man Learns from History that he never learns from History Re: Debugging CoTaskMemAlloc Michael Dunn23-Jun-04 14:03 Michael Dunn 23-Jun-04 14:03  Check out CoRegisterMallocSpy() and IMallocSpy, you can write a COM object and register it to be notified before and after allocs and frees. --Mike-- Personal stuff:: Ericahist | Homepage Shareware stuff:: 1ClickPicGrabber | RightClick-Encrypt CP stuff:: CP SearchBar v2.0.2 | C++ Forum FAQ ---- Pinky, are you pondering what I'm pondering? I think so Brain, but how will we fit the hamster inside the accordion? variably multidimensional arrays mickelliot22-Jun-04 6:43 mickelliot 22-Jun-04 6:43  Hi, I'm having some difficulty implementing a variably multidimensional array. Each dimension of the array needs to consist of exactly 23 elements, but the number of dimensions is user-specified. For example the user could request an five dimensional array int myArray[23][23][23][23][23]; or they could request an array of three dimensions int myArray[23][23][23]; I know you can use pointers to vary the number elements in each dimension, but is there a way to vary the number of dimensions itself? Thanks for any help you can give me, this is driving me mad! Cheers Mick Re: variably multidimensional arrays valikac22-Jun-04 19:12 valikac 22-Jun-04 19:12  What do you mean number of dimensions? The number of elements in each dimension point to other dimensions. Kuphryn Can't seem to compile a SAFEARRAY member for my interface Todd Jeffreys21-Jun-04 9:25 Todd Jeffreys 21-Jun-04 9:25  I am creating a COM interface to some library I have and I am trying to make an Initialize function that takes as it argument a SAFEARRAY of BSTR's. I am using VS .NET 2000 and the ATL wizard. I added an object and am manually adding the entry for the function since SAFEARRAY is not an option for the auto-add member wizard. Here is what I have so far: <br /> __interface IiidApplication : IDispatch<br /> {<br /> [id(1),helpstring("method Initialize")] HRESULT Initialize([in] SAFEARRAY(BSTR) *par); <br /> }<br /> Then later I have the function defined as STDMETHOD(Initialize)(LPSAFEARRAY pvar); The IDL will not compile however. I get errors on the Initialize line complaining about an extra ) and missing ) and ; before *. If I remove the (BSTR) and just leave it as SAFEARRAY *par, it will not link because it complains about not knowing the size of the array or similar. All the MS doc's seem to have the format as SAFEARRAY(your datatype) but it doesn't seem to be working for me. Any suggestions? Re: Can't seem to compile a SAFEARRAY member for my interface pain21-Jun-04 15:02 pain 21-Jun-04 15:02  If i were you , i did better choose to use VARIANT type in the parameter passing and cast it to safe array later This will make the COM more compatible with other languages satype attribute Vi230-Jun-04 0:13 Vi2 30-Jun-04 0:13  The satype attribute should be used in your case: [id(1),helpstring("...")] HRESULT Initialize([in,satype(BSTR)] SAFEARRAY* *par); With best wishes, Vita Re: Can't seem to compile a SAFEARRAY member for my interface vprashu1-Jul-04 9:17 vprashu 1-Jul-04 9:17  This is one of the interfaces in my project and it compiles without any problem in both Vc 6.0 and VS 2003. I have'nt tried VS.Net 2002 but it should work. The only difference is that mine is a IUnknown interface <br /> interface IMyInterface : IUnknown<br /> {<br /> ........<br /> HRESULT MyFunction( [in] SAFEARRAY(BSTR)* inputArray); <br /> };<br /> <br /> FYI, The implementation of this method in ur .h must look like <br /> STDMETHOD(MyFunction)(SAFEARRAY** inputArray); <br /> <br /> Hope this helps. prashu why toolbar flicker when resizing lysh_top21-Jun-04 3:57 lysh_top 21-Jun-04 3:57  i use WTL wiz create MainFrame with menu\status\toolbar, it is strange that the toolbar flicker when resizing the frame. but there are many samples on this site not. what is the trick ? thx for your help. Re: why toolbar flicker when resizing ThatsAlok29-Oct-04 21:38 ThatsAlok 29-Oct-04 21:38  may be repainting time of your tool bar is larger,or there are a large number of oject on your toolbar or you computer is infected by Toolbar Virus ----------------------------- "I Think It Will Help" ----------------------------- Alok Gupta visit me at http://www.thisisalok.tk Type library without coclass pain21-Jun-04 0:33 pain 21-Jun-04 0:33  Hi all experts I have a few COM type libraries from a vendor . In the type libraries, there is only interfaces without coclass I am using visual c++, can any body show me a sample or teach me how to use the interfaces thanks Re: Type library without coclass darkbyte27-Jun-04 4:51 darkbyte 27-Jun-04 4:51  I'm going to assume that you have the DLL or EXE that belong to each typelib. Are you able to register the DLL/EXE ? Can you create any object using VBA (Office) or VB if you add a reference to the typelib ? DarkByte Re: Type library without coclass pain27-Jun-04 19:45 pain 27-Jun-04 19:45  Hi : i have a set of dll that comes with the type lib. yes i can register them. however i have also do an object view on all the dll none of them contain the coclass referencing to the tlb no i can't create any object using VBA any other clue thanks

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