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Loosely speaking, BSTR is a strange beast, it is zero-terminated like a standard C-string, but it is prefixed by its length like a Pascal one (dont' worry about that, there are API like SysAllocString, or even classes, like _bstr_t, that do the job for you).
That stated, BSTR is used for automation, so, if you have to interact with automation clients (for instance, scripting languages) then you have to use BSTR (BTW your server also needs to implement a dual interface...). On the other hand, if your client is a standard Window application, written in C/C++, you can go also with char * (also Visual Basic code will be able to access you component, in a way similar to the one used to access Win32 API functionalities).
Hope that helps.
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.
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hi,
I've a COM object created in C++ , used in C# . I need to pass a string to that COM method, but always when I send string from C# , only first character occurs on C++ side.
COM Method:
STDMETHODIMP Initialize(LPTSTR a, LPTSTR b);
{
cout << "a: " << a << " b:" << b << endl;
....
}
if I call this method on that COM object (wrapped in C#)
IMyObject.Initialize("one", "two");
only thing i get in console is
a b:t
(instead of "a:one b:two")
how can i get whole size of string ??
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here you pass as array may be it solve ur problem
Sujit
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Try to send StringBuilder instances from C# application..
Cheers,
Suresh
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Have a look at this [^].
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.
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Hello,
You need to use BSTR instead of LPTSTR in your server.
Regards
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Hi,
I'm creating a COM object single dll server, which will be used in managed code, in C#. I'm having a little trouble with types . I need to declare method wich will have one input argument and one output argument, both of string type (in C#). Now I work with arguments :
C++
HRESULT Method([in] unsigned char const* source, [out, retval] unsigned char* output);
which are (in C#) converted to :
byte Method(ref byte source);
1. what kind of declaration I need in C++, so it would be transformed to string Method(string source) (in C#);
2. How to convert that kind to char* (in C++).
thanks
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try using BSTR in C++
Cheers,
Suresh
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In my application I got hr=S_FALSE.
at the end of function retun the green color turned error
give the following error and ask about break or continue the application.
on mouse move on green arrow got following ?
The code has called into another function.when that function is finished, this is the next statement that will be executed.
<br />
<br />
HRESULT Encoder :: ListSystemProfileForEnocder(HWND hFromEncodeProFile)<br />
{<br />
<br />
<br />
HRESULT hr;<br />
IWMEncoder* pEncoder;<br />
IWMEncProfileCollection* pProColl;<br />
IWMEncProfile* pPro;<br />
long lCount;<br />
int i;<br />
<br />
hr = CoInitialize(NULL); <BIG>Return S_FALSE </BIG><br />
<br />
if ( SUCCEEDED( hr ) )<br />
{<br />
hr = CoCreateInstance(CLSID_WMEncoder,<br />
NULL,<br />
CLSCTX_INPROC_SERVER,<br />
IID_IWMEncoder,<br />
(void**) &pEncoder);<br />
}<br />
<br />
if ( SUCCEEDED( hr ) )<br />
{<br />
hr = pEncoder->get_ProfileCollection(&pProColl);<br />
}<br />
if ( SUCCEEDED( hr ) )<br />
{<br />
hr = pProColl->get_Count(&lCount);<br />
}<br />
<br />
for (i=0; i<lCount; i++)<br />
{<br />
CComBSTR bstrName = NULL;<br />
if ( SUCCEEDED( hr ) )<br />
{<br />
hr = pProColl->Item(i, &pPro);<br />
}<br />
if ( SUCCEEDED( hr ) )<br />
{<br />
hr = pPro->get_Name(&bstrName);<br />
}<br />
<br />
SendMessage(hFromEncodeProFile,CB_ADDSTRING,i,reinterpret_cast<LPARAM>((LPCTSTR)bstrName));<br />
<br />
}<br />
<br />
if ( pProColl )<br />
{<br />
pProColl->Release();<br />
pProColl = NULL;<br />
}<br />
if ( pPro )<br />
{<br />
pPro->Release();<br />
pPro = NULL;<br />
}<br />
if ( pEncoder )<br />
{<br />
pEncoder->Release();<br />
pEncoder = NULL;<br />
}<br />
<br />
return( hr ); <br />
<br />
} <br />
The code has called into another function.when that function is finished, this is the next statement that will be executed. <br />
<br />
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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When ::CoInitialize[Ex](...) returns S_FALSE it means that the COM library has already been initialized for the calling thread.
Don't forget to match each call ::CoInitialize[Ex](...) with a call to ::CoUninitialize(...), even those that return S_FALSE. You haven't done so in the code you posted.
"It's supposed to be hard, otherwise anybody could do it!" - selfquote
"High speed never compensates for wrong direction!" - unknown
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is before return (hr);
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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I'm trying to generate .eml files with CDO 2000. But I got problems if the attachment's file name contains multi-lauguage characters. Then the attachment name will become ???????.
I tried two ways:
1. Set the file name directly with raw text.
2. Encoding the header (content-disposition) with RCF1522.
But I still got the same result.
Actually, I can call GetFileName() to retrieve the filename before writing stream to file, and it was fine. But something wrong happened when it generates the file.
Thanks a lot.
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Dear all,
I m new to COM world, having basic knowledge about it.
I have to redesign a simple DLL project to COM DLL Server so that it can incorporate with existing application with least changes.
What kind of approach i have to follow in order to complete this task ...
Waiting for your suggestion ...
Thanks..
"I only fail when i give up "
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Basically you want to write a COM wrapper around a Simple win32 Dll isnt it?
Does this Simple win32 dll contains exported Classes? or simple C functions?
Cheers,
Suresh
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Thanks for your kind reply ...
Yes a COM wrapper around a Simple win32 Dll. This win32 dll contains exported simple functions ...
Is this a fine approach or should i have start a project from start having all those functions of exported Classes in COM Server Dll.
Thanks...
"I only fail when i give up "
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Yeah, the approach is fine, but remember to distribute both the DLL's when you are publishing your application.
Cheers,
Suresh
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Hi,
Want to ask one more thing..
I have loaded the Admin.dll in my COM dll server. Is it possible that i can marshal pointer of my custom class from DLL Server to client for some specific processing or may u plz suggest any other possible approach for this case.
Thanks.
"I only fail when i give up "
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Can anyone please help me or give me some sample code? I need to create an ATL COM service (not a DLL) which has a dummy interface.. say. add 2 numbers.. After creating the service, i want to register it as a windows service. Then i want to create a client which connects to this service and uses the interface.. (adds 2 numbers)
I have searched online and there is not a decent article which explains the process step by step... Any help in this regard will be very useful.
Thanks in advance!!!!
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Hai all,
-> I have a "COM Server Exe" , with connection point.
->And I made my COM Object class Singleton by using
Macro "DECLARE_CLASSFACTORY_SINGLETON"
-> My Com Cleint is a Dialog Based Programme .I started 5 clients by
clicking on same exe.
-> Whenever the client starts , It will set up all the connection points
-> I am able to call a COM Method( for eg: my_ComFun() ) by clicking a
button on my dialog box
-> From inside my_ComFun() I am firing an event to my client .
implementation of my_ComFun()
/**************************************************************/
STDMETHODIMP CMyServer::my_ComFun(int i)
{
Fire_MyEvent(i);
return S_OK;
}
/**************************************************************/
->Whenever I am Firing events from my COM Server(Using function
Fire_MyEvent() ) , All my clients are
getting function calls , since my COM Server is a Singleton class.
* My Requirement is to prevent this broadcasting and direct the function
calls from COM to that specific client which calls the Servers my_ComFun(),
by keeping the COM Server Singleton.
Thanks in Advance.
George
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Hello,
I've written an ActiveX for IE in VS2005 C# .Net 2.0.
It supports RfID and GPS via COM-Port.
On my machine it runs great.
Now I wrote a setup with VS 2005.
I think I'm to set "vsdrpCOMSelfReg" for registering.
But it doesn't work.
It accepts only "vsdrpCOM"
After installation I called it in IE. It dosn't work.
When IE is open and I want to uninstall it by setup - Setup say "no, is in use."
I think, I'm not so far from target?!?
Can anyone help me?
I didn't find an good artikel in the internet.
Thanks a lot.
Additional:
In my IE I see the ActiveX in AddOns, but as File is listed "mscoree.dll"
What's that?
"Herausgeber" / Publisher is emty.
Maybe, it helps you.
Thanks a lot.
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how to create set up file in COM addins project. and how to install in client system. what r the requrements of clients system please urgent
send me important codes in the above projects
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How To Load Google Toolbar For Dialog??
Google Toolbar ClsID:{2318C2B1-4965-11d4-9B18-009027A5CD4F}
Code:
bool CShowToolbarDlg::LoadIEToolbar( CString strCLSID )
{
CLSID clsid;
WCHAR wsz[MAX_PATH];
::MultiByteToWideChar(CP_ACP, 0, strCLSID, -1, wsz, MAX_PATH);
HRESULT hr = CLSIDFromString(wsz, &clsid);
if ( hr != NOERROR )
return false;
::CoInitialize (NULL);
IUnknown* puk;
hr = ::CoCreateInstance(clsid, NULL, CLSCTX_INPROC_SERVER, IID_IUnknown, (void**)&puk);
if (FAILED(hr))
return false;
IDeskBand *pdb;
hr = puk->QueryInterface(IID_IDeskBand, (void**)&pdb);
HWND hBand;
if (SUCCEEDED(hr))
{
pdb->GetWindow(&hBand);
if(hBand == 0)
return false;
CWnd *pWnd = CWnd::FromHandle(hBand);
}
m_pReBar = new CReBar();
m_pReBar->Create(this);
CWnd *pWnd = CWnd::FromHandle(hBand);
if(pWnd==NULL) return false;
m_pReBar->AddBar(pWnd,NULL,NULL, RBBS_BREAK);
REBARBANDINFO rbbi;
rbbi.cbSize = sizeof(rbbi);
rbbi.fMask = RBBIM_CHILDSIZE | RBBIM_IDEALSIZE | RBBIM_SIZE;
rbbi.cxMinChild = 0;
rbbi.cyMinChild = 10;
rbbi.cx = rbbi.cxIdeal = 250;
UINT nCount = m_pReBar->GetReBarCtrl().GetBandCount();
m_pReBar->GetReBarCtrl().SetBandInfo(nCount-1, &rbbi);
return true;
}
Error:
pdb->GetWindow(&hBand);
if(hBand == 0)
return false;
Why hBand is NULL??
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Hi
I’m creating one windows service in my own purpose
Using msxml4.dll.
The process of service is to fetch the data from exchange server through webdav SEARCH METHOD
When i use this coding in windows form normal button click event , it works fine,
When I convert into windows service, it throws the error
The coding is below
MSXML2.XMLHTTP objXMLHTTP = new MSXML2.XMLHTTP();
writemethod("After Initialize");
System.Xml.XmlDataDocument xmlDOMParams = new System.Xml.XmlDataDocument();
objXMLHTTP.open("SEARCH", strInboxURL,false,strAliasName, strPassword);
objXMLHTTP.setRequestHeader("Content-type", "text/xml");
objXMLHTTP.setRequestHeader("Depth", "1");
string strXML;
strXML = "" +
" = \'DAV:\'>" +
"" +
"SELECT \"urn:schemas:httpmail:fromemail\"," +
------------------
---------etc…
objXMLHTTP.send(strXML); // Error Raised
The Error Raised in when i send the xml query
Any suggestion,please reply
We are using c#
Regards,
Arunkumar S
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