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.
So I'm using COM to access a third party program, I use the following Method to acquire property from server:
HRESULT ConnectToHYSYS::OLEMethod(int nType, VARIANT * pvResult, IDispatch * pDisp, LPOLESTR ptName, int cArgs...){
if (!pDisp) return E_FAIL;
va_list marker;
va_start(marker, cArgs);
DISPPARAMS dp = { NULL, NULL, 0, 0 };
DISPID dispidNamed = DISPID_PROPERTYPUT;
DISPID dispID;
char szName[200];
// Convert down to ANSI
WideCharToMultiByte(CP_ACP, 0, ptName, -1, szName, 256, NULL, NULL);
// Get DISPID for name passed...
HRESULT hr = pDisp->GetIDsOfNames(IID_NULL, &ptName, 1, LOCALE_USER_DEFAULT, &dispID);
if (FAILED(hr)) {
return hr;
}
// Allocate memory for arguments...
VARIANT * pArgs = new VARIANT[cArgs + 1];
// Extract arguments...
for (int i = 0; i < cArgs; i++) {
pArgs[i] = va_arg(marker, VARIANT);
}
// Build DISPPARAMS
dp.cArgs = cArgs;
dp.rgvarg = pArgs;
// Handle special-case for property-puts!
if (nType & DISPATCH_PROPERTYPUT) {
dp.cNamedArgs = 1;
dp.rgdispidNamedArgs = &dispidNamed;
}
// Make the call!
hr = pDisp->Invoke(dispID, IID_NULL, LOCALE_SYSTEM_DEFAULT, nType, &dp, pvResult, NULL, NULL);
if (FAILED(hr)) {
return hr;
}
// End variable-argument section...
va_end(marker);
delete[] pArgs;
return hr;
}
When I try to access an object in Collection through the following Method:
void ConnectToHYSYS::GetMaterialStream(int index) {
HRESULT hr;
VARIANT result;
VariantInit(&result);
hr = OLEMethod(DISPATCH_PROPERTYGET, &result, hyStreams, L"Item", 1, index);
CheckForHr(hr);
hyStream = result.pdispVal;}
It returns the hyStream member only if index=0; I checked the following:
1- hyStreams (the collection) pointer is not NULL
2- The member with index Im trying to access exists (The collection has 36 hyStreams but fails to get any hyStream with index more than 0)
3- When Debugging, the error happens when I make the Call
hr = pDisp->Invoke(dispID, IID_NULL, LOCALE_SYSTEM_DEFAULT, nType, &dp, pvResult, NULL, NULL);
Where hr returns above mentioned error...
Can you figure out where is the problem?
Thank you
The problem was in the type that was passed (index type), I think all kinds of types going through COM has to b kind of object.. anyways, changing it to _variant_t and including (without it, u get nasty errors of linking and stuff), the problem was solved and I could loop through the whole collection.
I searched how to formatting text to .doc/.docx file for weeks , but i don't found any good solution.
So my question is:
How to formatting text to output .doc/.docx file? (bold, center etc.)
Although your question is poorly formatted, I will do my best to help out.
Microsoft has a support page on using Microsoft Office formatting in C++. It looks like a pretty tough process.
The file you are concerned with is :
Word 2002 | msword.olb
Here is a codeguru link that attempts to address your issue, it might be somewhat out of date. It allows you to
CreateBlankDocument()
AppendText(CString szText)
GetLine(int nLine)
OpenWordFile(CString szFileName)
SaveWordFileAs(CString szFileName)
Okay : this Microsoft Word Automation post teaches you full functionality in automating a word document. My apologies for the wall of text to follow.
#include "stdafx.h"
#include <ole2.h>
//
// AutoWrap() - Automation helper function...
//
HRESULT AutoWrap(int autoType, VARIANT *pvResult, IDispatch *pDisp,
LPOLESTR ptName, int cArgs...)
{
// Begin variable-argument list...
va_list marker;
va_start(marker, cArgs);
if(!pDisp) {
MessageBox(NULL, "NULL IDispatch passed to AutoWrap()",
"Error", 0x10010);
_exit(0);
}
// Variables used...
DISPPARAMS dp = { NULL, NULL, 0, 0 };
DISPID dispidNamed = DISPID_PROPERTYPUT;
DISPID dispID;
HRESULT hr;
char buf[200];
char szName[200];
// Convert down to ANSI
WideCharToMultiByte(CP_ACP, 0, ptName, -1, szName, 256, NULL, NULL);
// Get DISPID for name passed...
hr = pDisp->GetIDsOfNames(IID_NULL, &ptName, 1, LOCALE_USER_DEFAULT,
&dispID);
if(FAILED(hr)) {
sprintf(buf,
"IDispatch::GetIDsOfNames(\"%s\") failed w/err0x%08lx",
szName, hr);
MessageBox(NULL, buf, "AutoWrap()", 0x10010);
_exit(0);
return hr;
}
// Allocate memory for arguments...
VARIANT *pArgs = new VARIANT[cArgs+1];
// Extract arguments...
for(int i=0; i<cArgs; i++) {
pArgs[i] = va_arg(marker, VARIANT);
}
// Build DISPPARAMS
dp.cArgs = cArgs;
dp.rgvarg = pArgs;
// Handle special-case for property-puts!
if(autoType & DISPATCH_PROPERTYPUT) {
dp.cNamedArgs = 1;
dp.rgdispidNamedArgs = &dispidNamed;
}
// Make the call!
hr = pDisp->Invoke(dispID, IID_NULL, LOCALE_SYSTEM_DEFAULT, autoType,
&dp, pvResult, NULL, NULL);
if(FAILED(hr)) {
sprintf(buf,
"IDispatch::Invoke(\"%s\"=%08lx) failed w/err 0x%08lx",
szName, dispID, hr);
MessageBox(NULL, buf, "AutoWrap()", 0x10010);
_exit(0);
return hr;
}
// End variable-argument section...
va_end(marker);
delete [] pArgs;
return hr;
}
int main(int argc, char* argv[])
{
// Initialize COM for this thread...
CoInitialize(NULL);
// Get CLSID for Word.Application...
CLSID clsid;
HRESULT hr = CLSIDFromProgID(L"Word.Application", &clsid);
if(FAILED(hr)) {
::MessageBox(NULL, "CLSIDFromProgID() failed", "Error",
0x10010);
return -1;
}
// Start Word and get IDispatch...
IDispatch *pWordApp;
hr = CoCreateInstance(clsid, NULL, CLSCTX_LOCAL_SERVER,
IID_IDispatch, (void **)&pWordApp);
if(FAILED(hr)) {
::MessageBox(NULL, "Word not registered properly",
"Error", 0x10010);
return -2;
}
// Make Word visible
{
VARIANT x;
x.vt = VT_I4;
x.lVal = 1;
AutoWrap(DISPATCH_PROPERTYPUT, NULL, pWordApp, L"Visible", 1,
x);
}
// Get Documents collection
IDispatch *pDocs;
{
VARIANT result;
VariantInit(&result);
AutoWrap(DISPATCH_PROPERTYGET, &result, pWordApp, L"Documents",
0);
pDocs = result.pdispVal;
}
// Call Documents.Open() to open C:\Doc1.doc
IDispatch *pDoc;
{
VARIANT result;
VariantInit(&result);
VARIANT x;
x.vt = VT_BSTR;
x.bstrVal = ::SysAllocString(L"C:\\Doc1.doc");
AutoWrap(DISPATCH_METHOD, &result, pDocs, L"Open", 1, x);
pDoc = result.pdispVal;
SysFreeString(x.bstrVal);
}
// Get BuiltinDocumentProperties collection
IDispatch *pProps;
{
VARIANT result;
VariantInit(&result);
AutoWrap(DISPATCH_PROPERTYGET, &result, pDoc,
L"BuiltinDocumentProperties", 0);
pProps = result.pdispVal;
}
// Get "Subject" from BuiltInDocumentProperties.Item("Subject")
IDispatch *pPropSubject;
{
VARIANT result;
VariantInit(&result);
VARIANT x;
x.vt = VT_BSTR;
x.bstrVal = ::SysAllocString(L"Subject");
AutoWrap(DISPATCH_PROPERTYGET, &result, pProps, L"Item", 1, x);
pPropSubject = result.pdispVal;
SysFreeString(x.bstrVal);
}
// Get the Value of the Subject property and display it
{
VARIANT result;
VariantInit(&result);
AutoWrap(DISPATCH_PROPERTYGET, &result, pPropSubject, L"Value",
0);
char buf[512];
wcstombs(buf, result.bstrVal, 512);
::MessageBox(NULL, buf, "Subject", 0x10000);
}
// Set the Value of the Subject DocumentProperty
{
VARIANT x;
x.vt = VT_BSTR;
x.bstrVal = ::SysAllocString(L"This is my subject");
AutoWrap(DISPATCH_PROPERTYPUT, NULL, pPropSubject, L"Value", 1,
x);
::MessageBox(NULL,
"Subject property changed, examine document.",
"Subject", 0x10000);
SysFreeString(x.bstrVal);
}
// Get CustomDocumentProperties collection
IDispatch *pCustomProps;
{
VARIANT result;
VariantInit(&result);
AutoWrap(DISPATCH_PROPERTYGET, &result, pDoc,
L"CustomDocumentProperties", 0);
pCustomProps = result.pdispVal;
}
// Add a new property named "CurrentYear"
{
VARIANT parm1, parm2, parm3, parm4;
parm1.vt = VT_BSTR;
parm1.bstrVal = SysAllocString(L"CurrentYear");
parm2.vt = VT_BOOL;
parm2.boolVal = false;
parm3.vt = VT_I4;
parm3.lVal = 1; //msoPropertyTypeNumber = 1
parm4.vt = VT_I4;
parm4.lVal = 1999;
AutoWrap(DISPATCH_METHOD, NULL, pCustomProps, L"Add", 4, parm4,
parm3, parm2, parm1);
::MessageBox(NULL, "Custom property added, examine document.",
"Custom Property", 0x10000);
SysFreeString(parm1.bstrVal);
}
// Get the custom property "CurrentYear" and delete it
IDispatch *pCustomProp;
{
VARIANT result;
VariantInit(&result);
VARIANT x;
x.vt = VT_BSTR;
x.bstrVal = ::SysAllocString(L"CurrentYear");
AutoWrap(DISPATCH_PROPERTYGET, &result, pCustomProps, L"Item",
1, x);
pCustomProp = result.pdispVal;
SysFreeString(x.bstrVal);
AutoWrap(DISPATCH_METHOD, NULL, pCustomProp, L"Delete", 0);
::MessageBox(NULL,
"Custom property removed, examine document.",
"Custom Property", 0x10000);
}
// Close the document without saving changes and quit Word
{
VARIANT x;
x.vt = VT_BOOL;
x.boolVal = false;
AutoWrap(DISPATCH_METHOD, NULL, pDoc, L"Close", 1, x);
AutoWrap(DISPATCH_METHOD, NULL, pWordApp, L"Quit", 0);
}
// Cleanup
pCustomProp->Release();
pCustomProps->Release();
pPropSubject->Release();
pProps->Release();
pDoc->Release();
pDocs->Release();
pWordApp->Release();
// Uninitialize COM for this thread...
CoUninitialize();
return 0;
}
One of the possible solution is to use libOPC. Documentation shows the simple examples(not so simple). Its cross-platform solution.
One of the simplest example
#include <opc/opc.h>
int main( int argc, const char* argv[] )
{
opcInitLibrary();
opcContainer *c=opcContainerOpen(_X("sample.opc"), OPC_OPEN_READ_WRITE, NULL, NULL);
opcPart part1=opcPartCreate(c, _X("part1.xml"), _X("text/plain"), 0);
opcPart part2=opcPartCreate(c, _X("part2.xml"), _X("text/plain"), 0);
opcContainerOutputStream *stream1=opcContainerCreateOutputStream(c, part1);
opcContainerOutputStream *stream2=opcContainerCreateOutputStream(c, part2);
// WRITE to stream1 and stream2 concurrently using
opcContainerWriteOutputStream(stream1, "HELLO", 5);
opcContainerWriteOutputStream(stream2, "HELLO", 5);
opcContainerWriteOutputStream(stream2, " WORLD", 6);
opcContainerWriteOutputStream(stream1, " WORLD", 6);
opcContainerCloseOutputStream(stream1);
opcContainerCloseOutputStream(stream2);
opcContainerClose(c, OPC_CLOSE_NOW);
opcFreeLibrary();
return 0;
}
If you want to read or write .docx files you will want to familiarize yourself with the EMCA-376 Standard for Office Open XML format documents. You can find a collection of these documents (various editions) on the EMCA website
You'll need a library, or to do Word automation.
Word's internal format is quite complex, and you don't want to try to do this directly.
EDIT
Just tested playcap.cpp and I'm also getting the same error so I know it's a not a fault with my code.
--
EDIT 2
Edited my code to preserve the goodMoniker pointer. Same error, however.
+if(pMoniker != goodMoniker)
+{
pMoniker->Release();
+}
--
Having a problem with getting my webcam to work with DirectShow. This line:
hr = goodMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)(&pCap));
returns the following error from MSVC++ 2010 EE:
First-chance exception at 0x777ff9d2 in WebcamControlTest.exe: 0xC0000008: An invalid handle was specified.
Full code here (ripped almost completely from MSDN):
#include <DShow.h>
#include <iostream>
int main(void)
{
IGraphBuilder* pGraph = NULL;
ICaptureGraphBuilder2* pBuild = NULL;
HRESULT hr;
//Initialize pGraph
hr = CoInitialize(NULL);
hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void**) &pBuild);
if(FAILED(hr))
{
printf("ERROR - Could not initialize COM library");
return 1;
}
//Initialize pBuild
hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void **) &pGraph);
if(FAILED(hr))
{
printf("ERROR - Could not create the Filter Graph Manager.");
return 2;
}
pBuild->SetFiltergraph(pGraph);
//Initialize pCap
ICreateDevEnum* pDevEnum = NULL;
IEnumMoniker* pEnum = NULL;
hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER, IID_ICreateDevEnum, reinterpret_cast<void**>(&pDevEnum));
if(SUCCEEDED(hr))
{
hr = pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pEnum, 0);
}
IMoniker* goodMoniker = NULL;
HWND hList;
IMoniker *pMoniker = NULL;
while(pEnum->Next(1, &pMoniker, NULL) == S_OK)
{
IPropertyBag* pPropBag;
hr = pMoniker->BindToStorage(0, 0, IID_IPropertyBag, (void**)(&pPropBag));
if(FAILED(hr))
{
pMoniker->Release();
continue;
}
VARIANT varName;
VariantInit(&varName);
hr = pPropBag->Read(L"Description", &varName, 0);
if(FAILED(hr))
{
hr = pPropBag->Read(L"FriendlyName", &varName, 0);
}
if(SUCCEEDED(hr))
{
for(int i=0;i<8;i++)
{
std::cout<<(char)*(varName.bstrVal + i);
}
char yn;
std::cin>>yn;
if(yn=='Y')
{
std::cout<<"SUCCESSFUL"<<std::endl;
goodMoniker = pMoniker;
VariantClear(&varName);
}
}
pPropBag->Release();
if(pMoniker != goodMoniker)
{
pMoniker->Release();
}
}
IBaseFilter* pCap;
hr = goodMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)(&pCap));
if(SUCCEEDED(hr))
{
hr = pGraph->AddFilter(pCap, L"Capture Filter");
}
hr = pBuild->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, pCap, NULL, NULL);
while(SUCCEEDED(hr));
pGraph->Release();
pBuild->Release();
pCap->Release();
}
It might be a driver problem as there is one device that works (a virtual driver for screencapping and not actual webcam input) but I've updated, uninstalled and reinstalled to no luck. Any ideas?
After saving a pointer in goodMoniker you release the object a couple of lines below (pMoniker->Release() ). Now goodMoniker points to a released object. You should have increased its reference count.
I'm new to COM and smartpointers, I'm trying to convert a project from raw pointers to CComPtr to avoid the hassle with memory management. I'm looking for some advice on how to properly use CComPointers when it comes to functions and scope in general. A sample of my code.
int DisplayDeviceInformation(IEnumMoniker * pEnum, IMoniker * pMoniker)
{
CComPtr<IPropertyBag> pPropBag = NULL;
while (pEnum->Next(1, &pMoniker, NULL) == S_OK)
{
HRESULT hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
if (FAILED(hr))
{
}
VARIANT var;
VariantInit(&var);
// Get description or friendly name.
hr = pPropBag->Read(L"Description", &var, 0);
if (FAILED(hr))
{
hr = pPropBag->Read(L"FriendlyName", &var, 0);
}
if (SUCCEEDED(hr))
{
printf("%S\n", var.bstrVal);
VariantClear(&var);
}
hr = pPropBag->Write(L"FriendlyName", &var);
// WaveInID applies only to audio capture devices.
hr = pPropBag->Read(L"WaveInID", &var, 0);
if (SUCCEEDED(hr))
{
printf("WaveIn ID: %d\n", var.lVal);
VariantClear(&var);
}
hr = pPropBag->Read(L"DevicePath", &var, 0);
if (SUCCEEDED(hr))
{
// The device path is not intended for display.
printf("Device path: %S\n", var.bstrVal);
VariantClear(&var);
}
}
return 0;
}
CComPtr<IMoniker> pMoniker = NULL;
CComPtr<IMoniker> pMoniker2 = NULL;
CComPtr<IEnumMoniker> pEnum = NULL;
hr = EnumerateDevices(CLSID_VideoInputDeviceCategory, &pEnum);
//pEnum->Next(1, &pMoniker,&cFetched);
if (SUCCEEDED(hr))
{
DisplayDeviceInformation(pEnum, pMoniker);
}
pEnum = NULL;
hr = EnumerateDevices(CLSID_AudioInputDeviceCategory, &pEnum);
//pEnum->Next(1, &pMoniker2,&cFetched);
if (SUCCEEDED(hr))
{
DisplayDeviceInformation(pEnum, pMoniker);
}
Basiclly, the first DisplayDeviceInformation(pEnum, pMoniker); gives a p==0 error. If I however uncomment the pEnum->Next(1, &pMoniker,&cFetched); it works. With raw pointers I don't have to do that since the code just skips to the next device. Any advice or help would make me outmost grateful, thanks in advance!
Where CComPtr gives you an assert failure, you are likely to have an issue with raw pointers as well. You just are not pre-warned and the problem comes up later, e.g. as a reference leak.
You don't seem to need IMoniker in global scope
You need to clear IMoniker pointer before supplying it for the enumerator
See below:
int DisplayDeviceInformation(IEnumMoniker* pEnum, IMoniker** ppSelectedMoniker)
{
CComPtr<IMoniker> pMoniker;
while (pEnum->Next(1, &pMoniker, NULL) == S_OK)
{
CComPtr<IPropertyBag> pPropBag; // You need it clear to start from for every moniker
HRESULT hr = pMoniker->BindToStorage(0, 0, IID_PPV_ARGS(&pPropBag));
// ...
if(we should stop enumeration and we are good with current moniker)
{
//ATLASSERT(ppSelectedMoniker != NULL);
*ppSelectedMoniker = pMoniker.Detach();
return ...
}
// ...
pMoniker.Release(); // You have to do this, so that next Next would accept empty CComPtr as an argument
}
return 0;
}
CComPtr<IEnumMoniker> pEnumVideoMoniker;
CComPtr<IMoniker> pSelectedVideoMoniker;
hr = EnumerateDevices(CLSID_VideoInputDeviceCategory, &pEnumVideoMoniker);
if (SUCCEEDED(hr))
DisplayDeviceInformation(pEnumVideoMoniker, &pSelectedVideoMoniker);
CComPtr<IEnumMoniker> pEnumAudioMoniker;
CComPtr<IMoniker> pSelectedAudioMoniker;
hr = EnumerateDevices(CLSID_AudioInputDeviceCategory, &pEnumAudioMoniker);
if (SUCCEEDED(hr))
DisplayDeviceInformation(pEnumAudioMoniker, &pSelectedAudioMoniker);