c++ - 将我的 DDiscMaster2Events 连接/链接到什么以进行驱动器更改事件。微软 COM 对象

Question

我打算在 mingw 上实现 Microsoft 的 COM 对象 DDiscMaster2Events 以获取磁盘驱动器更改事件。我找不到这方面的任何例子。我已经让 DDiskFormat2DataEvents 正常工作，所以我希望它与此类似。在 DDiskFormat2DataEvents 中，我必须将我的 DDiskFormat2DataEvents 与 IDiskFormat2Data 连接起来才能获取事件。这通常使用 AfxConnectionAdvise 方法完成。我需要将我的 DDiscMaster2Events 事件接收器连接到什么 com 对象，以接收磁盘更改事件？ Visual Studio c++ 示例应该可以回答我的问题。谢谢

Answer 1

这篇文章COM Connection Points中有一些关于如何接收COM事件的信息Thottam R. Sriram 着。

根据其内容，这样的想法可能对您有用:

#include <imapi2.h>
#include <iostream>
#include <cassert>

class DiscMaster2EventsSink : public DDiscMaster2Events {
  public:
    STDMETHOD(NotifyDeviceAdded)(IDispatch *object, BSTR uniqueId)
    {
      std::cout << "NotifyDeviceAdded(...)\n";
      return S_OK;
    }

    STDMETHOD(NotifyDeviceRemoved)(IDispatch *object, BSTR uniqueId)
    {
      std::cout << "NotifyDeviceRemoved(...)\n";
      return S_OK;
    }

  public:
    // The uninteresting stuff follows...

    DiscMaster2EventsSink()
      : m_refCount(1)
    {
    }

    STDMETHOD(QueryInterface)(REFIID riid, void **ppv)
    {
      *ppv = NULL;

      if (riid == IID_IUnknown)
        *ppv = static_cast<void*>(static_cast<IUnknown*>(this));
      else if (riid == IID_IDispatch)
        *ppv = static_cast<void*>(static_cast<IDispatch*>(this));
      else if (riid == __uuidof(DDiscMaster2Events))
        *ppv = static_cast<void*>(static_cast<DDiscMaster2Events*>(this));

      if (*ppv) {
        AddRef();
        return S_OK;
      }

      return E_NOINTERFACE;
    }

    STDMETHOD_(ULONG, AddRef)()
    {
      return InterlockedIncrement(&m_refCount);
    }

    STDMETHOD_(ULONG, Release)()
    {
      ULONG result = InterlockedDecrement(&m_refCount);
      if (result == 0)
        delete this;
      return result;
    }

    STDMETHOD(GetIDsOfNames)(REFIID riid, LPOLESTR *rgszNames, UINT cNames, LCID lcid, DISPID *rgDispId)
    {
      return E_NOTIMPL;
    }

    STDMETHOD(GetTypeInfo)(UINT iTInfo, LCID lcid, ITypeInfo **ppTInfo)
    {
       return E_NOTIMPL;
    }

    STDMETHOD(GetTypeInfoCount)(UINT *pctinfo)
    {
      *pctinfo = 0;
      return S_OK;
    }

    STDMETHOD(Invoke)(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags, DISPPARAMS *pDispParams,
      VARIANT *pVarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr)
    {
      return E_NOTIMPL;
    }

  private:
    ULONG m_refCount;
};

int main()
{
  HRESULT hr;

  hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
  assert(SUCCEEDED(hr));

  IDiscMaster2* pDiscMaster2;
  hr = CoCreateInstance(__uuidof(MsftDiscMaster2), NULL, CLSCTX_ALL, __uuidof(IDiscMaster2), (void**)&pDiscMaster2);
  assert(SUCCEEDED(hr));

  IConnectionPointContainer* pCPC;
  hr = pDiscMaster2->QueryInterface(IID_IConnectionPointContainer, (void**)&pCPC);
  assert(SUCCEEDED(hr));

  IConnectionPoint* pCP;
  hr = pCPC->FindConnectionPoint(IID_DDiscMaster2Events, &pCP);
  assert(SUCCEEDED(hr));

  DiscMaster2EventsSink* pSink = new DiscMaster2EventsSink();

  IUnknown* pSinkUnk;
  hr = pSink->QueryInterface(IID_IUnknown, (void**)&pSinkUnk);
  assert(SUCCEEDED(hr));

  DWORD dwAdvise;
  hr = pCP->Advise(pSinkUnk, &dwAdvise);
  assert(SUCCEEDED(hr));

  std::cout << "OK...\n";
  std::cin.get();

  pSinkUnk->Release();
  pSink->Release();
  pCP->Release();
  pCPC->Release();
  pDiscMaster2->Release();
  CoUninitialize();
  return 0;
}

据我所知，它编译并运行良好(一直是 S_OK)，但我看不到任何事件 - 可能是因为我没有外部光驱来创建任何设备添加/删除事件。

(同样显然，使用一些 C++ COM 辅助类会更好。)

希望它仍然可以帮助您，也许即使在 MinGW 下也有一些变化。