atl

I have a COM dll , which is consumed by .NET applications using COM Inter-op. In one of the CoClasses , there is an Interface called IT6TrackData and it has one get property called TrackData From the IDL file: Interface IT6TrackData { [propget, id(1)] HRESULT TrackData([out, retval] SAFEARRAY(BYTE) *pVal); } When the TLB file is viewed for the above IDL file, it shows the property as trackData ( t in lower case) For some reason the Client application were referring to this property as trackData and everything was working fine until now. As part of enhancement the above Interface was upgraded

Here's a code sample creating a COM object: CComPtr<IBaseFilter> pFilter; auto hr = CoCreateInstance(CLSID_DMOWrapperFilter, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, reinterpret_cast<void**>(&pFilter)); I've seen somewhere that checking if CoCreateInstance() succeeded should look like this: if (SUCCEEDED(hr) && pFilter != nullptr) { // code goes here } What if I would check only hr ? Wouldn't it be enough? Should I also check that filter != nullptr ? //would this be enough? if (SUCCEEDED(hr)) { // code goes here } This question also concerns other COM methods like QueryInterface() . Having

Given the encoding of the project is probably Unicode (but not for sure) what is the best way of converting ATL::CString to QString? What I have thought of is this: CString c(_T("SOME_TEXT")); //... std::basic_string<TCHAR> intermediate((LPCTSTR)c); QString q; #ifdef _UNICODE q = QString::fromStdWString(intermediate); #else q = QString::fromStdString(intermediate); #endif Do you think that it works? Any other ideas? You don't need the intermediate conversion to a std::string . The CString class can be treated as a simple C-style string; that is, an array of characters. All you have to do is

When including atlwin.h from the Microsoft ATL libraries in Visual Studio 2013 building will result in numerous complier errors about undefined elements. i.e. #include <atlwin.h> class MainWnd : public CWindowImpl<MainWnd> {}; "CWindowImpl: base class is not defined" error. or HMONITOR is not defined This does not occur when building using VS2010. How can I fix that? The problem is with the targeted version of windows in the stdafx.h file from MSDN Visual C++ no longer supports targeting Windows 95, Windows 98, Windows ME, or Windows NT. If your WINVER or _WIN32_WINNT macros are assigned to

I've implemented an IFilter as a native VC++ ATL in-proc COM server. Windows Search wouldn't use it - it creates an instance of my IFilter and then executes a bunch of QueryInterface() calls, specifically: IMarshal IStdMarshalInfo something with {4C1E39E1-E3E3-4296-AA86-EC938D896E92} interface id and a couple of others. Since my IFilter only implements IFilter, IPersist and IPersistFile most of the calls return E_NOINTERFACE, so Windows Search just releases my object and does nothing. Why is it querying for those interfaces and how do I work the problem around? Shay Erlichmen Windows tries

I'm trying to get a simple OpenCV sample working in C++ on Windows and my C++ is more than rusty. The sample is fairly simple: #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> #include <iostream> using namespace cv; using namespace std; int main( int argc, char** argv ) { if( argc != 2) { cout <<" Usage: display_image ImageToLoadAndDisplay" << endl; return -1; } Mat image; image = imread(argv[1], IMREAD_COLOR); // Read the file if(! image.data ) // Check for invalid input { cout << "Could not open or find the image" << std::endl ; return -1; } namedWindow( "Display

I have an out-of-process COM server written in C++, which is called by some C# client code. A method on one of the server's interfaces returns a large BSTR to the client, and I suspect that this is causing a memory leak. The code works, but I am looking for help with marshalling-out BSTRs. Simplifying a bit, the IDL for the server method is HRESULT ProcessRequest([in] BSTR request, [out] BSTR* pResponse); and the implementation looks like: HRESULT MyClass::ProcessRequest(BSTR request, BSTR* pResponse) { USES_CONVERSION; char* pszRequest = OLE2A(request); char* pszResponse = BuildResponse