|
I tried using CComBSTRs in my class but I had some strange things happening when I did that made me switch back to straight BSTRs. When I accessed the property the CComBSTRs were storing the first time from a skeleton VB project, they worked great. Any subsequent attempts to get the property only returned an empty string (""). Not sure what was going on there. Any thoughts?
Also, is there a way to test if a BSTR has been allocated before calling ::SysFreeString() on a BSTR? Or, can you safely call ::SysFreeString() on a BSTR that hasn't been ::SysAllocString()'d yet?
|
|
|
|
|
First, when you were returning your CComBSTR to the VB app, were you making a copy of the string? If not, then the VB very well could have been deallocating the string.
You should set your pointer to NULL when it isn't pointing to an allocated string. Thus in your destructor you can check for NULL to see if you need to free it. Otherwise, you might try to free someone else's memory or invalid memory and crash the program.
Tim Smith
I know what you're thinking punk, you're thinking did he spell check this document? Well, to tell you the truth I kinda forgot myself in all this excitement. But being this here's CodeProject, the most powerful forums in the world and would blow your head clean off, you've got to ask yourself one question, Do I feel lucky? Well do ya punk?
|
|
|
|
|
Also You can use bstr_t,it is very easier to use
it.It doesn't need to use SysAllocString() and SysFreeeString() for it.
Mazy
"So,so you think you can tell,
Heaven from Hell,
Blue skies from pain,...
How I wish,how I wish you were here."
Wish You Were Here-Pink Floyd-1975
|
|
|
|
|
Hello gurus,
I want to connect to the events of a custom browser that basically hosts IE webbrowser control, from my application. After the user launches the custom browser,I want to be able to detect events like OnNavigate,DocumentComplete etc. How can this be done? Would appreciate any help, ideas and code.
TIA.
#define MOSTLY_LEAN_AND_MEAN
|
|
|
|
|
Connect to the WebBrowser control events. Here is a sample : http://msdn.microsoft.com/library/en-us/dnwebgen/html/bho.asp?frame=true#bho_getevents
|
|
|
|
|
Will third party browsers load a BHO too?
#define MOSTLY_LEAN_AND_MEAN
|
|
|
|
|
Help me. !I have an exercise:
Build an Active X that allow communicate with COM Ports:
-Allow user choosing port (COM1, COM2, COM3, COM4)
-Allow setting parameters: speed, parity, data bit, stop bit…
-Have methods: Open, Close, Flush ports
-Have method: Send & Receive data (char or string) through ports
-Allow setting time for end of transfer data (time-out transfer)
-Allow setting time for testing port (loop-back tested time)
-Auto enabled when there's an event from ports.
Can you help me ! (I use VC++)
Hung Son
Hung Son
|
|
|
|
|
Hi ,
Can someone tell me how to use MFC classes, like
CPropertySheet in ATL EXE.
Thanks,
Sansky 
God is Good, all the Time.
All the Time, God is Good.
|
|
|
|
|
There's such a function in VBScript as TypeName which returns the coclass name of the passed object.
How to do the same using:
- JScript
- Compiler COM Support Classes (C++)
- API (C++)
?
tx
(H) Serge
|
|
|
|
|
TypeName return the type of the variant which was passed as argument. To do the same in C++ check the vt member of the VARIANT data ( it can be VT_BSTR, VT_I4, VT_BOOL, etc)
|
|
|
|
|
Hi,
When i try to access IADsWInNTSystemInfo interface, i am getting "undeclared
identifer" error. I have included the Iads.h file, but the file doesn't contain
the interface. Where will i get the latest header file. Anbody help??
Thanx,
Sangeetha.
|
|
|
|
|
I would look in the different versions of Platform SDK.
Andres Manggini.
Buenos Aires - Argentina.
|
|
|
|
|
The version which i downloaded from Microsoft site is ADSI SDK version 2.5. I am not able to find any updates or fixes. Please do keep me posted on this.
Thanx,
Sangeetha.
|
|
|
|
|
Hello I had created an Activex component
I try to create it dynamically with :
Set MyTotoObject = CreateObject("TotoViewOCX.TotoView")
In this cas I can only acces the function of my object I can not access
the extender functions.
So I can not displaying it.
I try another method:
Set MyTotoObject = MMI.Controls.Add("TotoViewOCX.TotoView", "MyToto")
With this mode I can only acces the extender methods, And I can displaying it.
but I need to use the function I have created.
Is it possible to create the object and displaying it with the possibility
to Use the functionnality i add inside
Thanks a lot Michael
|
|
|
|
|
Try to use the typelib while creating the control and then use the New keyword to instantiate it. First set a reference to the control. then create it
Dim obj as new MyProject.MyActiveXControlClass
Set obj = new MyProject.MyActiveXControlClass
obj.CallMethod
#define MOSTLY_LEAN_AND_MEAN
|
|
|
|
|
Hi all,
In my server implementation, I have the following code:
// Create a new CComEnum<> of IUser* interfaces
typedef CComObject< CComEnum<ienumuser, &iid_ienumuser,=""
="" iuser*,="" _copyinterface<iuser=""> > > EnumUser;
EnumUser* pNewEnum = NULL;
EnumUser::CreateInstance(&pNewEnum); // This is the line with error
However, when I tried to compile my server, I receive the following:
error C2259: 'CComObject<class atl::ccomenum<struct="" ienumuser,&struct="" _guid="" const="" iid_ienumuser,struct="" iuser="" *,class="" atl::_copyinterface<struct="">,class ATL::CComSingleT
hreadModel> >' : cannot instantiate abstract class due to following members:
c:\program files\microsoft visual studio\vc98\atl\include\atlcom.h(4403) : while compiling class-template member function 'long __stdcall ATL::CComObject<class atl::ccomenum<struct="" ienumuser,&struct="" _guid="" const="" iid_ienumuser,struct="" iuser="" *,
class="" atl::_copyinterface<struct="">,class ATL::CComSingleThreadModel> >::CreateInstance(class ATL::CComObject<class atl::ccomenum<struct="" ienumuser,&struct="" _guid="" const="" iid_ienumuser,struct="" iuser="" *,class="" atl::_copyinterface<struct="">,class AT
L::CComSingleThreadModel> > ** )'
I have IEnumUser declared in the server idl file, and IUser declared in a separate dll.
Does anyone know what I have done wrong? Your help is much apprepriated.
Sunny
|
|
|
|
|
Sorry, the error message got cutoff. It should be:
error C2259: 'CComObject<class atl::ccomenum<struct="" ienumuser,&struct="" _guid="" const="" iid_ienumuser,struct="" iuser="" *,class=""
atl::_copyinterface<struct="">,class ATL::CComSingleT
hreadModel> >' : cannot instantiate abstract class due to following
members:
c:\program files\microsoft visual studio\vc98\atl\include\atlcom.h
(4403) : while compiling class-template member function 'long __stdcall
ATL::CComObject<class atl::ccomenum<struct="" ienumuser,&struct="" _guid=""
const="" iid_ienumuser,struct="" iuser="" *,
class="" atl::_copyinterface<struct="">,class
ATL::CComSingleThreadModel> >::CreateInstance(class
ATL::CComObject<class atl::ccomenum<struct="" ienumuser,&struct="" _guid=""
const="" iid_ienumuser,struct="" iuser="" *,class="" atl::_copyinterface<struct=""
iuser="">,class ATL::CComSingleThreadModel> > ** )'
|
|
|
|
|
I call CoInitialize(NULL) in a DLL, and after some processing, I call CoUnitialize in the same DLL. This causes the app using the DLL to crash (rather spectacularly) in another un-related part of the code.
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
|
|
|
|
|
When that ocurss I prefer to use the CoInitialize and the CoUnitialize out of the DLL, before and after to call the function into the dll
Best Regards
Carlos Antollini.
Sonork ID 100.10529 cantollini
|
|
|
|
|
I tried moving the CoInit/CoUninit to the class in the app that actually uses the DLL.
COM has to be available the entire time that the DLL lives in the program space because I have interfaces that might persist between calls to the DLL's functions.
There is truly strange stuff happening.
It might even be better if I called CoInit in OnInitInstance in the app instead.
"...the staggering layers of obscenity in your statement make it a work of art on so many levels." - Jason Jystad, 10/26/2001
|
|
|
|
|
Isn't it recommended to call CoInitializeEx(). I have had problems with CoInitialise() before and changing to ...Ex may help.
Dave.
|
|
|
|
|
Did you freed all the interface references?
E.g. YourInterface->Release(), or if you are using smart pointers, setting them to NULL?
I have seen a crash before when I forgot to free all the references before I called CoUninitialize().
Hope it helps,
Sunny
|
|
|
|
|
Hi,
I have stumbled across a problem again, and this time, it is on retrieving an element from a SAFEARRAY. The following code shows what I am trying to achieve:
// Creates a user
IUser* pUser4 = NULL;
CoCreateInstance( __uuidof( User ), NULL, CLSCTX_INPROC_SERVER,
IID_IUser, (void**)&pUser4 );
// Store my first name into it
pUser4->put_FirstName( L"Sunny" );
// Creates a variant that contains an array of type IUnknown pointers
_variant_t* userArray = new _variant_t;
userArray->vt = VT_ARRAY | VT_UNKNOWN;
// Create the array
SAFEARRAY* pSA;
SAFEARRAYBOUND bounds = { 1, 0 };
pSA = SafeArrayCreate( VT_UNKNOWN, 1, &bounds );
// Turn my pUser4 pointer into the IUnknown pointer
IUnknown* pUnk = NULL;
pUser4->QueryInterface( IID_IUnknown, (void**)&pUnk );
// put the IUnknown pointer into the array, and store the array
// into the variant
long a = 0;
SafeArrayPutElement( pSA, &a, pUnk );
userArray->parray = pSA;
// Retrieve the element
SAFEARRAY* ans = userArray->parray;
IUnknown* pUnk2 = NULL;
SafeArrayGetElement( ans, &a, pUnk2 ); // problem occurs
IUser* pUser5 = NULL;
pUnk2->QueryInterface( IID_IUser, (void**)&pUser5 );
BSTR first;
pUser5->get_FirstName( &first );
//======================== END
The problem arises when I tried to get the IUnknown pointer from the array by calling SafeArrayGetElement. I looked at the debugger, and it showed that the address of pUnk2 is 0x00000000.
I am wondering if anybody known what I have done wrong?
Help is apprepriated 
Sunny
|
|
|
|
|
I'm not sure the problem is that but I know if you want to access the buffer of SAFEARRAY,after you create it you have to use SafeArrayAccessData() method,and after you finished working with it you have to
use SafeArrayUnAccessData().
Mazy
"So,so you think you can tell,
Heaven from Hell,
Blue skies from pain,...
How I wish,how I wish you were here."
Wish You Were Here-Pink Floyd-1975
|
|
|
|
|
Hi,
I'm using ::OleCreate to activate an Excel worksheet (Excel.Sheet) in-place in an MDI child window. The problem is I want to control the out-of-process server instance (Excel.Application) that is instancing the worksheets.
The default Windows behviour seems to either create the Excel.Sheet instances from whichever server was launched first, or just creates a new server if no server is activated.
Does anyone know of a way of specifying which server the out-of-process object is created in?
Many thanks in advance.
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
