Related
I have problem with IWMPEvents, which I advised successfully but never raised. Here is how I create embeded Windows Media Player:
HRESULT MyWMP::setURL(wchar_t* url)
{
return pMediaPlayer->put_URL(url); // Load and play songs successfully;
}
bool MyWMP::CreatePlayer()
{
HRESULT hr;
const CLSID CLSID_WindowsMediaPlayer = { 0x6BF52A52, 0x394A, 0x11d3,{ 0xB1, 0x53, 0x00, 0xC0, 0x4F, 0x79, 0xFA, 0xA6 } };
hr = ::OleCreate(CLSID_WindowsMediaPlayer, IID_IOleObject, OLERENDER_DRAW, 0, this, this, (void**)&oleObject);
if (SUCCEEDED(hr) && oleObject)
{
if (SUCCEEDED(hr)) hr = oleObject->SetClientSite(this);
if (SUCCEEDED(hr)) hr = OleSetContainedObject(oleObject, TRUE);
if (SUCCEEDED(hr))
{
RECT posRect;
::SetRect(&posRect, -300, -300, 300, 300);
hr = oleObject->DoVerb(OLEIVERB_INPLACEACTIVATE, NULL, this, -1, this->hwnd, &posRect);
}
hr = oleObject->QueryInterface(&pMediaPlayer);
}
if (FAILED(hr) || !pMediaPlayer)
{
MessageBox(NULL, L"Create Browser failed!", L"Error", MB_ICONERROR);
return false;
}
return true;
}
MyWMP::MyWMP(HWND parentHWND, HINSTANCE hInstance) :
isFullyCreated(false)
{
OleInitialize(NULL);
HRESULT hr = E_FAIL;
IConnectionPointContainer* container = nullptr;
IUnknown* punk = nullptr;
this->parentHWND = parentHWND;
this->hwnd = CreateWindow(L"Static", NULL, WS_CHILD | WS_VISIBLE, 221, 0, 300, 300, parentHWND, NULL, hInstance, 0);
iComRefCount = 0;
::SetRect(&rObject, 0, 0, 300, 300);
if (CreatePlayer())
{
hr = pMediaPlayer->get_settings(&pMediaPlayerSettings);
if (SUCCEEDED(hr) && pMediaPlayerSettings)
{
pMediaPlayerSettings->put_autoStart(VARIANT_TRUE);
pMediaPlayerSettings->put_volume(100);
}
hr = pMediaPlayer->QueryInterface(IID_IConnectionPointContainer, (void**)&container);
if (SUCCEEDED(hr) && container) hr = container->FindConnectionPoint(__uuidof(IWMPEvents), &callback);
if (FAILED(hr) && container)
{
hr = container->FindConnectionPoint(__uuidof(_WMPOCXEvents), &callback);
}
if (SUCCEEDED(hr) && callback)
{
CWMPEventDispatch *cw = new CWMPEventDispatch();
IUnknown *cwUnk = NULL;
if (SUCCEEDED(cw->QueryInterface(IID_IUnknown, (void**)&cwUnk)))
{
if (SUCCEEDED(hr) && container)
{
hr = callback->Advise(cwUnk, &eventCookie);
if (SUCCEEDED(hr) && eventCookie)
{
isFullyCreated = true; // Set breakpoint here and is triggered
// by debugger
// hr = S_OK
}
}
}
if (cwUnk) cwUnk->Release();
}
if (punk) punk->Release();
if (container) container->Release();
}
}
Bellow is the CWMPEventDispatch class. I set breakpoint at all IDispatch functions and none of them get triggered by debugger. When I load new songs, play/pause (on the embeded UI control buttons), these functions is never called.
// CWMPEventDispatch.h : Declaration of the event dispatcher
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
#include "stdafx.h"
#include "wmpids.h"
#include "wmp.h"
class CWMPEventDispatch :
public IWMPEvents,
public _WMPOCXEvents
{
public:
// ----- IUnknown -----
virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void**ppvObject) override;
virtual ULONG STDMETHODCALLTYPE AddRef(void);
virtual ULONG STDMETHODCALLTYPE Release(void);
// IDispatch methods
STDMETHOD(GetIDsOfNames)(REFIID /*riid*/,
__in_ecount(cNames) LPOLESTR FAR * /*rgszNames*/,
unsigned int /*cNames*/,
LCID /*lcid*/,
DISPID FAR * /*rgDispId*/)
{
return(E_NOTIMPL);
}
STDMETHOD(GetTypeInfo)(unsigned int /*iTInfo*/,
LCID /*lcid*/,
ITypeInfo FAR *FAR * /*ppTInfo*/)
{
return(E_NOTIMPL);
}
STDMETHOD(GetTypeInfoCount)(unsigned int FAR * /*pctinfo*/)
{
return(E_NOTIMPL);
}
STDMETHOD(Invoke)(DISPID dispIdMember,
REFIID /*riid*/,
LCID /*lcid*/,
WORD /*wFlags*/,
DISPPARAMS FAR* pDispParams,
VARIANT FAR* /*pVarResult*/,
EXCEPINFO FAR* /*pExcepInfo*/,
unsigned int FAR* /*puArgErr*/);
private:
int iComRefCount;
};
#include "stdafx.h"
#include "myWMPEventDispatch.h"
#pragma region ----- IUnknown -----
ULONG STDMETHODCALLTYPE CWMPEventDispatch::AddRef(void) { return ++iComRefCount; }
ULONG STDMETHODCALLTYPE CWMPEventDispatch::Release(void) { return --iComRefCount; }
HRESULT STDMETHODCALLTYPE CWMPEventDispatch::QueryInterface(REFIID riid, void**ppvObject)
{
if (riid == __uuidof(IUnknown)) *ppvObject = static_cast<IDispatch*>(this);
else if (riid == __uuidof(IDispatch)) *ppvObject = static_cast<IDispatch*>(this);
else if (riid == __uuidof(IWMPEvents)) *ppvObject = static_cast<IWMPEvents*>(this);
else if (riid == __uuidof(_WMPOCXEvents)) *ppvObject = static_cast<_WMPOCXEvents*>(this);
else
return E_NOINTERFACE;
AddRef();
return S_OK;
}
#pragma endregion
HRESULT CWMPEventDispatch::Invoke(
DISPID dispIdMember,
REFIID /*riid*/,
LCID /*lcid*/,
WORD /*wFlags*/,
DISPPARAMS FAR* pDispParams,
VARIANT FAR* /*pVarResult*/,
EXCEPINFO FAR* /*pExcepInfo*/,
unsigned int FAR* /*puArgErr*/)
{
if (!pDispParams)
return E_POINTER;
if (pDispParams->cNamedArgs != 0)
return DISP_E_NONAMEDARGS;
HRESULT hr = DISP_E_MEMBERNOTFOUND;
return(hr);
}
Question:
Why my IWMPEvents functions are never called, and how to fix it?
I attack full source code as a 7z archive. You can download it here.
Environment: Win 10 x64, VS 2017 Community
This piece of code:
if (SUCCEEDED(hr) && container) hr = container->FindConnectionPoint(__uuidof(IWMPEvents), &callback);
if (FAILED(hr) && container)
{
hr = container->FindConnectionPoint(__uuidof(_WMPOCXEvents), &callback);
}
Will succeed on the first line, so you will hook events on the IWMPEvents only, you will not continue and hook _WMPOCXEvents.
IWMPEvents are early-bound (IUnknown derived) events, so the Media Player will indeed call IWMPEvents::PlayStateChange(...) IWMPEvents::StatusChange(...) etc. but it won't call IDispatch::Invoke with corresponding DISPIDs.
If you want IDispatch events, just remove the first FindConnectionPoint, or call both.
The folowing code is a part of my application.
I want to get a value from file save dialog using a editbox.
So i use AddEditBox function and GetEditBoxText to return value.
I enter "2000.0" in the editbox but the rturn value is Empty.
what is the problem?
wstring GetSaveFileForMakeDif(double & MinDistance) {
const DWORD CONTROL_GROUP = 5001;
const DWORD CONTROL_LABEL = 5002;
const DWORD CONTROL_EDITBOX_MINDIST = 5003;
wstring ret(L"");
HRESULT hr = S_FALSE;
IFileDialogCustomize *pfdc = NULL;
// Create a new common open file dialog.
IFileSaveDialog *pfd = NULL;
hr = CoCreateInstance(CLSID_FileSaveDialog, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pfd));
if (SUCCEEDED(hr))
{
DWORD dwOptions;
hr = pfd->GetOptions(&dwOptions);
// Set the title of the dialog.
if (SUCCEEDED(hr)) {
hr = pfd->SetTitle(L"Select Files");
hr = pfd->SetFileName(L"outputfile");
hr = pfd->SetDefaultExtension(L"txt");
}
// Set up the customization.
hr = pfd->QueryInterface(IID_PPV_ARGS(&pfdc));
if (SUCCEEDED(hr))
{
hr = pfdc->StartVisualGroup(CONTROL_GROUP, L"");
if (SUCCEEDED(hr))
hr = pfdc->AddText(CONTROL_LABEL, L"Min Distance:");
if (SUCCEEDED(hr))
hr = pfdc->AddEditBox(CONTROL_EDITBOX_MINDIST, L"2000.0");
pfdc->EndVisualGroup();
}
// Show the open file dialog.
if (SUCCEEDED(hr))
{
hr = pfd->Show(hMainWindow);
if (SUCCEEDED(hr))
{
IShellItem *psi = NULL;
hr = pfd->GetResult(&psi);
wchar_t *pszPath = new wchar_t[MAX_PATH];
psi->GetDisplayName(SIGDN_FILESYSPATH, &pszPath);
if (SUCCEEDED(hr))
{
ret = pszPath;
wchar_t * txt = NULL;
hr = pfdc->GetEditBoxText(CONTROL_EDITBOX_MINDIST, &txt);
//txt return L""
MinDistance = _wtof(txt);
}
}
}
pfd->Release();
}
pfdc->Release();
return ret;
};
Event handling is needed to catch the values before the dialog closes.
There is a complete MSDN example available here:
Common File Dialog Sample
At the moment the download link does not seem to be available. The example below shows how to catch the event in OnFileOk
Note that you need CoTaskMemFree to release memory which had been allocated by GetEditBoxText
#include <windows.h>
#include <shobjidl.h>
#include <shlwapi.h>
#include <new>
#pragma comment(linker, "\"/manifestdependency:type='Win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
#pragma comment(lib, "Shlwapi.lib")
// Controls
#define CONTROL_GROUP 2000
#define CONTROL_LABEL 5002
#define CONTROL_EDITBOX_MINDIST 5003
class CDialogEventHandler : public IFileDialogEvents, public IFileDialogControlEvents
{
public:
// IUnknown methods
IFACEMETHODIMP QueryInterface(REFIID riid, void** ppv) {
static const QITAB qit[] = {
QITABENT(CDialogEventHandler, IFileDialogEvents),
QITABENT(CDialogEventHandler, IFileDialogControlEvents),
{ 0 },
};
return QISearch(this, qit, riid, ppv);
}
IFACEMETHODIMP_(ULONG) AddRef() {
return InterlockedIncrement(&_cRef);
}
IFACEMETHODIMP_(ULONG) Release() {
long cRef = InterlockedDecrement(&_cRef);
if (!cRef)
delete this;
return cRef;
}
// IFileDialogEvents methods
IFACEMETHODIMP OnFileOk(IFileDialog *pfd);
IFACEMETHODIMP OnFolderChange(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnFolderChanging(IFileDialog *, IShellItem *) { return S_OK; };
IFACEMETHODIMP OnHelp(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnSelectionChange(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnShareViolation(IFileDialog *, IShellItem *, FDE_SHAREVIOLATION_RESPONSE *) { return S_OK; };
IFACEMETHODIMP OnTypeChange(IFileDialog *) { return S_OK; };
IFACEMETHODIMP OnOverwrite(IFileDialog *, IShellItem *, FDE_OVERWRITE_RESPONSE *) { return S_OK; };
// IFileDialogControlEvents methods
IFACEMETHODIMP OnItemSelected(IFileDialogCustomize *, DWORD, DWORD) { return S_OK; };
IFACEMETHODIMP OnButtonClicked(IFileDialogCustomize *, DWORD) { return S_OK; };
IFACEMETHODIMP OnCheckButtonToggled(IFileDialogCustomize *, DWORD, BOOL) { return S_OK; };
IFACEMETHODIMP OnControlActivating(IFileDialogCustomize *, DWORD) { return S_OK; };
CDialogEventHandler() : _cRef(1) { };
private:
~CDialogEventHandler() { };
long _cRef;
};
// Instance creation helper
HRESULT CDialogEventHandler_CreateInstance(REFIID riid, void **ppv)
{
*ppv = NULL;
CDialogEventHandler *pDialogEventHandler = new (std::nothrow) CDialogEventHandler();
HRESULT hr = pDialogEventHandler ? S_OK : E_OUTOFMEMORY;
if (SUCCEEDED(hr))
{
hr = pDialogEventHandler->QueryInterface(riid, ppv);
pDialogEventHandler->Release();
}
return hr;
}
//EDIT BEGIN ***************************
// IFileDialogEvents methods
IFACEMETHODIMP CDialogEventHandler::OnFileOk(IFileDialog *fileDialog)
{
IFileDialogCustomize *fileCustomize = NULL;
fileDialog->QueryInterface(IID_PPV_ARGS(&fileCustomize));
wchar_t *buf;
fileCustomize->GetEditBoxText(IDC_EDTI1, &buf);
MessageBox(0, buf, 0, 0);
CoTaskMemFree(buf);
fileCustomize->Release();
return S_OK;
}
//EDIT END *****************************
// This code snippet demonstrates how to add custom controls in the Common File Dialog.
HRESULT AddCustomControls()
{
// CoCreate the File Open Dialog object.
IFileDialog *pfd = NULL;
HRESULT hr = CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pfd));
if (SUCCEEDED(hr))
{
// Create an event handling object, and hook it up to the dialog.
IFileDialogEvents *pfde = NULL;
DWORD dwCookie = 0;
hr = CDialogEventHandler_CreateInstance(IID_PPV_ARGS(&pfde));
if (SUCCEEDED(hr))
{
// Hook up the event handler.
hr = pfd->Advise(pfde, &dwCookie);
if (SUCCEEDED(hr))
{
// Set up a Customization.
IFileDialogCustomize *pfdc = NULL;
if (SUCCEEDED(pfd->QueryInterface(IID_PPV_ARGS(&pfdc))))
{
pfdc->StartVisualGroup(CONTROL_GROUP, L"");
pfdc->AddText(CONTROL_LABEL, L"Min Distance:");
pfdc->AddEditBox(CONTROL_EDITBOX_MINDIST, L"2000.0");
pfdc->EndVisualGroup();
pfdc->Release();
}
else
{
// Unadvise here in case we encounter failures before we get a chance to show the dialog.
pfd->Unadvise(dwCookie);
}
}
pfde->Release();
}
if (SUCCEEDED(hr))
{
// Now show the dialog.
hr = pfd->Show(NULL);
if (SUCCEEDED(hr))
{
// You can add your own code here to handle the results.
}
// Unhook the event handler.
pfd->Unadvise(dwCookie);
}
pfd->Release();
}
return hr;
}
int APIENTRY wWinMain(HINSTANCE, HINSTANCE, PWSTR, int)
{
CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
AddCustomControls();
CoUninitialize();
return 0;
}
I'm trying hook custom Credentential Provider UI, based on ICredentialProvider interface.
Using this guide(Vtable Patching) , i'm succesufly hook COM interface.
But trouble with hooking GetCredentenialAt method, i'm set vtable index equal to 10, and try relogin.
LogonUI screen blinking on :Ctrl+Alt+Del Screen:.
my source code:
#include "stdafx.h"
#include "VtableHooks.h"
#include "credentialprovider.h"
namespace Hook
{
STDMETHODIMP GetCredentialAt(IUnknown* This, DWORD dwIndex, ICredentialProviderCredential** ppcpc);
STDMETHODIMP QueryInterface(IUnknown* This, REFIID riid, void **ppvObject);
}
struct Context
{
Context(): m_Name("Hooked object"){}
PVOID m_OriginalQueryInterface;
PVOID m_OriginalGetCredentialAt;
ATL::CComBSTR m_Name;
};
std::auto_ptr<Context> g_Context;
HRESULT HookMethod(IUnknown* original, PVOID proxyMethod, PVOID* originalMethod, DWORD vtableOffset)
{ PVOID* originalVtable = *(PVOID**)original;
if (originalVtable[vtableOffset] == proxyMethod)
return S_OK;
*originalMethod = originalVtable[vtableOffset];
originalVtable[vtableOffset] = proxyMethod;
return S_OK;
}
HRESULT InstallComInterfaceHooks(IUnknown* originalInterface, REFIID riid)
{
HRESULT hr = S_OK;
if (riid == IID_ICredentialProvider)
{
// Only single instance of a target object is supported in the sample
if (g_Context.get())return E_FAIL;
ATL::CComPtr<ICredentialProvider> so;
HRESULT hr = originalInterface->QueryInterface(IID_ICredentialProvider, (void**)&so);
if (FAILED(hr)) return hr; // we need this interface to be present
// remove protection from the vtable
DWORD dwOld = 0;
if (!::VirtualProtect(*(PVOID**)(originalInterface), sizeof(LONG_PTR), PAGE_EXECUTE_READWRITE, &dwOld))
return E_FAIL;
// hook interface methods
g_Context.reset(new Context);
HookMethod(so, (PVOID)Hook::QueryInterface, &g_Context->m_OriginalQueryInterface, 0);
HookMethod(so, (PVOID)Hook::GetCredentialAt, &g_Context->m_OriginalGetCredentialAt, 10);
}
return hr;
}
typedef HRESULT (WINAPI *QueryInterface_T)(IUnknown* This, REFIID riid, void **ppvObject);
STDMETHODIMP Hook::QueryInterface(IUnknown* This, REFIID riid, void **ppvObject)
{
QueryInterface_T qi = (QueryInterface_T)g_Context->m_OriginalQueryInterface;
HRESULT hr = qi(This, riid, ppvObject);
return hr;
}
typedef HRESULT(WINAPI *GetCredentialAt_T)(IUnknown* This, DWORD dwIndex, ICredentialProviderCredential** ppcpc);
STDMETHODIMP Hook::GetCredentialAt(IUnknown* This, DWORD dwIndex, ICredentialProviderCredential** ppcpc)
{
GetCredentialAt_T qi = (GetCredentialAt_T)g_Context->m_OriginalGetCredentialAt;
HRESULT hr = qi(This, dwIndex, ppcpc);
return hr;
}
Using IDA, i'm showing load 3rd custom dll. This Dll break interface.
I have successfully compiled and registered a direct show filter. Now I want to use it in my code. But the call to COCreateInstance returns errorcode E_NOINTERFACE.
Here is the registration code of my filter
#include "MyFilter.h"
#include <aviriff.h>
static WCHAR g_wszName[] = L"MyFilter";
CFactoryTemplate g_Templates[] =
{
{
g_wszName,
&CLSID_MyFilter,
MyFilter::CreateInstance,
NULL,
NULL
}
};
int g_cTemplates = sizeof(g_Templates) / sizeof(g_Templates[0]);
// Declare media type information.
FOURCCMap fccMap = FCC('MRLE');
REGPINTYPES sudInputTypes = { &MEDIATYPE_Video, &GUID_NULL };
REGPINTYPES sudOutputTypes = { &MEDIATYPE_Video, (GUID*)&fccMap };
// Declare pin information.
REGFILTERPINS sudPinReg[] = {
// Input pin.
{ TEXT("PinInput0"), FALSE, // Rendered?
FALSE, // Output?
FALSE, // Zero?
FALSE, // Many?
0, 0,
1, &sudInputTypes // Media types.
},
{ TEXT("PinInput1"), FALSE,
FALSE,
FALSE,
FALSE,
0, 0, 1, &sudInputTypes
},
{
TEXT("PinInput2"), FALSE,
FALSE,
FALSE,
FALSE,
0, 0, 1, &sudInputTypes
},
// Output pin.
{ 0, FALSE, // Rendered?
TRUE, // Output?
FALSE, // Zero?
FALSE, // Many?
0, 0,
1, &sudOutputTypes // Media types.
}
};
// Declare filter information.
REGFILTER2 rf2FilterReg = {
1, // Version number.
MERIT_DO_NOT_USE, // Merit.
4, // Number of pins.
sudPinReg // Pointer to pin information.
};
STDAPI DllRegisterServer(void)
{
HRESULT hr = AMovieDllRegisterServer2(TRUE);
if (FAILED(hr))
{
return hr;
}
IFilterMapper2 *pFM2 = NULL;
hr = CoCreateInstance(CLSID_FilterMapper2, NULL, CLSCTX_INPROC_SERVER,
IID_IFilterMapper2, (void **)&pFM2);
if (SUCCEEDED(hr))
{
hr = pFM2->RegisterFilter(
CLSID_MyFilter, // Filter CLSID.
g_wszName, // Filter name.
NULL, // Device moniker.
&CLSID_VideoCompressorCategory, // Video compressor category.
g_wszName, // Instance data.
&rf2FilterReg // Filter information.
);
pFM2->Release();
}
return hr;
}
STDAPI DllUnregisterServer()
{
HRESULT hr = AMovieDllRegisterServer2(FALSE);
if (FAILED(hr))
{
return hr;
}
IFilterMapper2 *pFM2 = NULL;
hr = CoCreateInstance(CLSID_FilterMapper2, NULL, CLSCTX_INPROC_SERVER,
IID_IFilterMapper2, (void **)&pFM2);
if (SUCCEEDED(hr))
{
hr = pFM2->UnregisterFilter(&CLSID_VideoCompressorCategory,
g_wszName, CLSID_MyFilter);
pFM2->Release();
}
return hr;
}
extern "C" BOOL WINAPI DllEntryPoint(HINSTANCE, ULONG, LPVOID);
BOOL APIENTRY DllMain(HANDLE hModule, DWORD dwReason, LPVOID lpReserved)
{
return DllEntryPoint((HINSTANCE)(hModule), dwReason, lpReserved);
}
And here the code that uses the filter
#include <DShow.h>
#include "MyFilter.h"
#include <streams.h>
IPin *GetPin(IBaseFilter *pFilter, PIN_DIRECTION PinDir)
{
BOOL bFound = FALSE;
IEnumPins *pEnum;
IPin *pPin;
pFilter->EnumPins(&pEnum);
while(pEnum->Next(1, &pPin, 0) == S_OK)
{
PIN_DIRECTION PinDirThis;
pPin->QueryDirection(&PinDirThis);
if (bFound = (PinDir == PinDirThis))
break;
pPin->Release();
}
pEnum->Release();
return (bFound ? pPin : 0);
}
int CALLBACK WinMain(
_In_ HINSTANCE hInstance,
_In_ HINSTANCE hPrevInstance,
_In_ LPSTR lpCmdLine,
_In_ int nCmdShow
)
{
CoInitialize(NULL);
IGraphBuilder* pGraph = NULL;
IMediaControl* pMediaControl = NULL;
IMediaEvent* pMediaEvent = NULL;
HRESULT hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_ALL, IID_IFilterGraph, (void **) &pGraph);
if(hr < 0)
{
return -1;
}
IBaseFilter* pSource = NULL;
pGraph->QueryInterface(IID_IMediaControl, (void **) pMediaControl);
pGraph->QueryInterface(IID_IMediaEvent, (void **) pMediaEvent);
pGraph->AddSourceFilter(TEXT("C:\\TEMP\\video1.avi"), 0, &pSource);
IPin* pSourceOut = GetPin(pSource, PINDIR_OUTPUT);
IBaseFilter* pAVISplitter = NULL;
CoCreateInstance(CLSID_AviSplitter, NULL,
CLSCTX_INPROC_SERVER,
IID_IBaseFilter,
(void**)&pAVISplitter);
IPin* pAvIIn = GetPin(pAVISplitter, PINDIR_INPUT);
pGraph->AddFilter(pAVISplitter, L"Splitter");
pGraph->Connect(pSourceOut, pAvIIn);
IPin* pAVIOut = GetPin(pAVISplitter, PINDIR_OUTPUT);
MyFilter* myfilter;
hr = CoCreateInstance(CLSID_MyFilter, NULL, CLSCTX_INPROC_SERVER, IID_MyFilter, (void **)& myfilter);
if(hr < 0)
{
return -1;
}
IPin* myfilterIn = myfilter->GetPin(0);
IPin* myFilterOut = myfilter->GetPin(3);
pGraph->Connect(pAVIOut, myfilterIn);
pGraph->Render(myFilterOut);
CoUninitialize();
return 0;
}
Simply calls the base class:
STDMETHODIMP MyFilter::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
return CBaseFilter::NonDelegatingQueryInterface(riid, ppv);
}
Also note that I can import my filter in graphedit
MyFilter::NonDelegatingQueryInterface is where you should look at
Simply calls the base class:
Compare to EzRGB24 sample, which - similarly to yours - adds custom interface. You need to update your project respectively.
//
// NonDelegatingQueryInterface
//
// Reveals IIPEffect and ISpecifyPropertyPages
//
STDMETHODIMP CEZrgb24::NonDelegatingQueryInterface(REFIID riid, void **ppv)
{
CheckPointer(ppv,E_POINTER);
if (riid == IID_IIPEffect) {
return GetInterface((IIPEffect *) this, ppv);
} else if (riid == IID_ISpecifyPropertyPages) {
return GetInterface((ISpecifyPropertyPages *) this, ppv);
} else {
return CTransformFilter::NonDelegatingQueryInterface(riid, ppv);
}
}
See this example Add Support for COM, when NonDelegatingQueryInterface requests IID_MyFilter, you have to return a pointer to that interface.
If your filter can be added in graphedit but not your application, maybe you have a 32/64 bit problem. The filter dll/ax needs to be compiled with the same bit width as your app, this applies to any dll not just Directshow.
Here's some other tips for Directshow programming in C++:
Use GraphStudioNext as you can compile it with debug symbols and 32/64 bit versions
Use ATL COM Smart Pointers to avoid memory leaks and messy code eg CComPtr pSmartFilter
CComPtr<IPin> myfilterIn;
myfilterIn.Attach(myfilter->GetPin(0));
// No need to Release myfilterIn as CComPtr will do it for you when it goes out of scope
What I want to do:
Write an application that listens to Office events. I want to listen to events from any instance opened on the machine. E.g. if I'm listening to BeforeDocumentSave in Word, then I want my sink for this method to be activated whenever any instance of Word on the host saves a document.
Another requirement is that I'm writing in C++ without MFC or ATL.
What I've done:
I've written a program that's supposed to listen to Word events. See the code below.
The problem:
It doesn't work - the event handlers are never entered, although I open a word application and do the actions that should trigger the events.
I have some specific questions, and of course any other input would be very welcome!
Questions:
Is it possible to listen to events from an application that wasn't started by me? In all the examples I found, the listening application starts the office application it wants to listen to.
In a microsoft howto (http://support.microsoft.com/kb/183599/EN-US/) I found the following comment:
However, most events, such as
Microsoft Excel's Workbook events, do
not start with DISPID 1. In such
cases, you must explicitly modify the
dispatch map in MyEventSink.cpp to
match the DISPIDs with the correct
methods.
How do I modify the dispatch map?
For now I've defined only Startup, Quit and DocumentChange, which take no arguments. The methods I really need do take arguments, specifically one of type Document. How do I define parameters of this type if I'm not using MFC?
Code:
Here's the header file for my project, followed by the C file:
#ifndef _OFFICEEVENTHANDLER_H_
#define _OFFICEEVENTHANDLER_H_
// 000209FE-0000-0000-C000-000000000046
static const GUID IID_IApplicationEvents2 =
{0x000209FE,0x0000,0x0000, {0xC0,0x00,0x00,0x00,0x00,0x00,0x00,0x46}};
struct IApplicationEvents2 : public IDispatch // Pretty much copied from typelib
{
/*
* IDispatch methods
*/
STDMETHODIMP QueryInterface(REFIID riid, void ** ppvObj) = 0;
STDMETHODIMP_(ULONG) AddRef() = 0;
STDMETHODIMP_(ULONG) Release() = 0;
STDMETHODIMP GetTypeInfoCount(UINT *iTInfo) = 0;
STDMETHODIMP GetTypeInfo(UINT iTInfo, LCID lcid, ITypeInfo **ppTInfo) = 0;
STDMETHODIMP GetIDsOfNames(REFIID riid, OLECHAR **rgszNames,
UINT cNames, LCID lcid, DISPID *rgDispId) = 0;
STDMETHODIMP Invoke(DISPID dispIdMember, REFIID riid, LCID lcid,
WORD wFlags, DISPPARAMS* pDispParams,
VARIANT* pVarResult, EXCEPINFO* pExcepInfo,
UINT* puArgErr) = 0;
/*
* IApplicationEvents2 methods
*/
STDMETHODIMP Startup();
STDMETHODIMP Quit();
STDMETHODIMP DocumentChange();
};
class COfficeEventHandler : IApplicationEvents2
{
public:
DWORD m_dwEventCookie;
COfficeEventHandler
(
) :
m_cRef(1),
m_dwEventCookie(0)
{
}
STDMETHOD_(ULONG, AddRef)()
{
InterlockedIncrement(&m_cRef);
return m_cRef;
}
STDMETHOD_(ULONG, Release)()
{
InterlockedDecrement(&m_cRef);
if (m_cRef == 0)
{
delete this;
return 0;
}
return m_cRef;
}
STDMETHOD(QueryInterface)(REFIID riid, void ** ppvObj)
{
if (riid == IID_IUnknown){
*ppvObj = static_cast<IApplicationEvents2*>(this);
}
else if (riid == IID_IApplicationEvents2){
*ppvObj = static_cast<IApplicationEvents2*>(this);
}
else if (riid == IID_IDispatch){
*ppvObj = static_cast<IApplicationEvents2*>(this);
}
else
{
char clsidStr[256];
WCHAR wClsidStr[256];
char txt[512];
StringFromGUID2(riid, (LPOLESTR)&wClsidStr, 256);
// Convert down to ANSI
WideCharToMultiByte(CP_ACP, 0, wClsidStr, -1, clsidStr, 256, NULL, NULL);
sprintf_s(txt, 512, "riid is : %s: Unsupported Interface", clsidStr);
*ppvObj = NULL;
return E_NOINTERFACE;
}
static_cast<IUnknown*>(*ppvObj)->AddRef();
return S_OK;
}
STDMETHOD(GetTypeInfoCount)(UINT* pctinfo)
{
return E_NOTIMPL;
}
STDMETHOD(GetTypeInfo)(UINT itinfo, LCID lcid, ITypeInfo** pptinfo)
{
return E_NOTIMPL;
}
STDMETHOD(GetIDsOfNames)(REFIID riid, LPOLESTR* rgszNames, UINT cNames,
LCID lcid, DISPID* rgdispid)
{
return E_NOTIMPL;
}
STDMETHOD(Invoke)(DISPID dispidMember, REFIID riid,
LCID lcid, WORD wFlags, DISPPARAMS* pdispparams, VARIANT* pvarResult,
EXCEPINFO* pexcepinfo, UINT* puArgErr)
{
return E_NOTIMPL;
}
// IApplicationEvents2 methods
void Startup();
void Quit();
void DocumentChange();
protected:
LONG m_cRef;
};
#endif // _OFFICEEVENTHANDLER_H_
The C file:
#include <windows.h>
#include <stdio.h>
#include "OfficeEventHandler.h"
#include "OCIdl.h"
int main()
{
CLSID clsid; // CLSID of automation object
HRESULT hr;
LPUNKNOWN punk = NULL; // IUnknown of automation object
LPDISPATCH pdisp = NULL; // IDispatch of automation object
IConnectionPointContainer *pConnPntCont;
IConnectionPoint *pConnPoint;
IUnknown *iu;
IID id;
COfficeEventHandler *officeEventHandler = new COfficeEventHandler;
CoInitialize(NULL);
hr = CLSIDFromProgID(OLESTR("Word.Application"), &clsid);
hr = CoCreateInstance(clsid, NULL, CLSCTX_SERVER,
IID_IUnknown, (void FAR* FAR*)&punk);
hr = punk->QueryInterface(IID_IConnectionPointContainer, (void FAR* FAR*)&pConnPntCont);
// IID for ApplicationEvents2
hr = IIDFromString(L"{000209FE-0000-0000-C000-000000000046}",&id);
hr = pConnPntCont->FindConnectionPoint( id, &pConnPoint );
hr = officeEventHandler->QueryInterface( IID_IUnknown, (void FAR* FAR*)&iu);
hr = pConnPoint->Advise( iu, &officeEventHandler->m_dwEventCookie );
Sleep( 360000 );
hr = pConnPoint->Unadvise( officeEventHandler->m_dwEventCookie );
if (punk) punk->Release();
if (pdisp) pdisp->Release();
CoUninitialize();
return hr;
}
// IApplicationEvents2 methods
void COfficeEventHandler::Startup()
{
printf( "In Startup\n" );
}
void COfficeEventHandler::Quit()
{
printf( "In Quit\n" );
}
void COfficeEventHandler::DocumentChange()
{
printf( "In DocumentChnage\n" );
}
Your number one problem is you don't run the message loop in the main thread and that causes the events to never reach your sink object. Calls form the COM server to your sink object are dispatched using Windows messages, so you have to run the message loop instead of simply calling Sleep() so that the incoming events are eventually dispatched to the sink object.
I found two problems in the code I gave here:
As sharptooth pointed out, Sleep is wrong here. It even causes the application I listen to to hang, or sleep. I put in a message loop as sharptooth suggested.
I hadn't implemented 'Invoke'. I thought that if I implemented the event methods themselves, they would be called by the application, but this is not the case. I had to implement invoke and make it switch on the dispid and call the different event methods. I found the dispid in the typelib. Looking at a method in the OLE viewer, I used the 'id' which apparently is the dispid.
Following is a corrected .cpp file. In the .h file the only correction is to change Invoke into a declaration instead of an implementation.
Two notes on the code:
I constructed it out of various examples I found, so you may find names or comments that seem irrelevant because they were taken from elsewhere.
To get the COM object I used either GetActiveObject or CoCreateInstance. The former works only if the event firing application is already running. The latter creates an invisible instance of it. For Word this worked well, possibly because if I open another Word instance its part of the same process. I haven't checked yet what happens if I open a new process, if the events would still be triggered.
Hope this helps!
#include <windows.h>
#include <stdio.h>
#include "OfficeEventHandler.h"
#include "OCIdl.h"
int main()
{
CLSID clsid; // CLSID of automation object
HRESULT hr;
LPUNKNOWN punk = NULL; // IUnknown of automation object
LPDISPATCH pdisp = NULL; // IDispatch of automation object
IConnectionPointContainer *pConnPntCont;
IConnectionPoint *pConnPoint;
IUnknown *iu;
IID id;
COfficeEventHandler *officeEventHandler = new COfficeEventHandler;
CoInitialize(NULL);
hr = CLSIDFromProgID(OLESTR("Word.Application"), &clsid);
/* hr = GetActiveObject( clsid, NULL, &punk );
*/ hr = CoCreateInstance(clsid, NULL, CLSCTX_SERVER,
IID_IUnknown, (void FAR* FAR*)&punk);
hr = punk->QueryInterface(IID_IConnectionPointContainer, (void FAR* FAR*)&pConnPntCont);
// IID for ApplicationEvents2
hr = IIDFromString(L"{000209FE-0000-0000-C000-000000000046}",&id);
hr = pConnPntCont->FindConnectionPoint( id, &pConnPoint );
hr = officeEventHandler->QueryInterface( IID_IUnknown, (void FAR* FAR*)&iu);
hr = pConnPoint->Advise( iu, &officeEventHandler->m_dwEventCookie );
MSG msg;
BOOL bRet;
while( (bRet = GetMessage( &msg, NULL, 0, 0 )) != 0 )
{
if (bRet == -1)
{
// handle the error and possibly exit
}
else
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
if( msg.message == WM_QUERYENDSESSION || msg.message == WM_QUIT || msg.message == WM_DESTROY )
{
break;
}
}
hr = pConnPoint->Unadvise( officeEventHandler->m_dwEventCookie );
if (punk) punk->Release();
if (pdisp) pdisp->Release();
CoUninitialize();
return hr;
}
// IApplicationEvents2 methods
void COfficeEventHandler::Startup()
{
printf( "In Startup\n" );
}
void COfficeEventHandler::Quit()
{
printf( "In Quit\n" );
}
void COfficeEventHandler::DocumentChange()
{
printf( "In DocumentChnage\n" );
}
STDMETHODIMP COfficeEventHandler::Invoke(DISPID dispIdMember, REFIID riid,
LCID lcid, WORD wFlags, DISPPARAMS* pdispparams, VARIANT* pvarResult,
EXCEPINFO* pexcepinfo, UINT* puArgErr)
{
//Validate arguments
if ((riid != IID_NULL))
return E_INVALIDARG;
HRESULT hr = S_OK; // Initialize
/* To see what Word sends as dispid values */
static char myBuf[80];
memset( &myBuf, '\0', 80 );
sprintf_s( (char*)&myBuf, 80, " Dispid: %d :", dispIdMember );
switch(dispIdMember){
case 0x01: // Startup
Startup();
break;
case 0x02: // Quit
Quit();
break;
case 0x03: // DocumentChange
DocumentChange();
break;
}
return S_OK;
}