Sample Code
Windows Driver Samples/ WPDHelloWorld sample driver for portable devices/ C++/ WpdBaseDriver.cpp/
#include "stdafx.h" #include "WpdBaseDriver.tmh" WpdBaseDriver::WpdBaseDriver() : m_cRef(1) { } WpdBaseDriver::~WpdBaseDriver() { } ULONG __stdcall WpdBaseDriver::AddRef() { InterlockedIncrement((long*) &m_cRef); return m_cRef; } _At_(this, __drv_freesMem(Mem)) ULONG __stdcall WpdBaseDriver::Release() { ULONG ulRefCount = m_cRef - 1; if (InterlockedDecrement((long*) &m_cRef) == 0) { delete this; return 0; } return ulRefCount; } HRESULT __stdcall WpdBaseDriver::QueryInterface( REFIID riid, void** ppv) { HRESULT hr = S_OK; if(riid == IID_IUnknown) { *ppv = static_cast<IUnknown*>(this); AddRef(); } else { *ppv = NULL; hr = E_NOINTERFACE; } return hr; } HRESULT WpdBaseDriver::DispatchWpdMessage(_In_ IPortableDeviceValues* pParams, _In_ IPortableDeviceValues* pResults) { HRESULT hr = S_OK; GUID guidCommandCategory = {0}; DWORD dwCommandID = 0; PROPERTYKEY CommandKey = WPD_PROPERTY_NULL; if (hr == S_OK) { hr = pParams->GetGuidValue(WPD_PROPERTY_COMMON_COMMAND_CATEGORY, &guidCommandCategory); CHECK_HR(hr, "Failed to get WPD_PROPERTY_COMMON_COMMAND_CATEGORY from input parameters"); } if (hr == S_OK) { hr = pParams->GetUnsignedIntegerValue(WPD_PROPERTY_COMMON_COMMAND_ID, &dwCommandID); CHECK_HR(hr, "Failed to get WPD_PROPERTY_COMMON_COMMAND_ID from input parameters"); } // If WPD_PROPERTY_COMMON_COMMAND_CATEGORY or WPD_PROPERTY_COMMON_COMMAND_ID could not be extracted // properly then we should return E_INVALIDARG to the client. if (FAILED(hr)) { hr = E_INVALIDARG; CHECK_HR(hr, "Failed to get WPD_PROPERTY_COMMON_COMMAND_CATEGORY or WPD_PROPERTY_COMMON_COMMAND_ID from input parameters"); } if (hr == S_OK) { CommandKey.fmtid = guidCommandCategory; CommandKey.pid = dwCommandID; if (CommandKey.fmtid == WPD_CATEGORY_OBJECT_ENUMERATION) { hr = m_ObjectEnum.DispatchWpdMessage(CommandKey, pParams, pResults); } else if (CommandKey.fmtid == WPD_CATEGORY_OBJECT_PROPERTIES) { hr = m_ObjectProperties.DispatchWpdMessage(CommandKey, pParams, pResults); } else if (CommandKey.fmtid == WPD_CATEGORY_OBJECT_RESOURCES) { hr = m_ObjectResources.DispatchWpdMessage(CommandKey, pParams, pResults); } else if (CommandKey.fmtid == WPD_CATEGORY_CAPABILITIES) { hr = m_Capabilities.DispatchWpdMessage(CommandKey, pParams, pResults); } else if (IsEqualPropertyKey(CommandKey, WPD_COMMAND_COMMON_GET_OBJECT_IDS_FROM_PERSISTENT_UNIQUE_IDS)) { hr = OnGetObjectIDsFromPersistentUniqueIDs(pParams, pResults); } else { hr = E_NOTIMPL; CHECK_HR(hr, "Unknown command %ws.%d received",CComBSTR(CommandKey.fmtid), CommandKey.pid); } } HRESULT hrTemp = pResults->SetErrorValue(WPD_PROPERTY_COMMON_HRESULT, hr); CHECK_HR(hrTemp, ("Failed to set WPD_PROPERTY_COMMON_HRESULT")); // Set to a success code, to indicate that the message was received. // the return code for the actual command's results is stored in the // WPD_PROPERTY_COMMON_HRESULT property. hr = S_OK; return hr; } /** * This method is called to initialize the driver object. * This is where the driver would set up it's I/O libraries * and so on. */ HRESULT WpdBaseDriver::Initialize() { return S_OK; } /** * This method is called to uninitialize the driver object. * In a real driver, this is where the driver would clean up * any resources held by this driver. */ VOID WpdBaseDriver::Uninitialize() { } /** * This method is called when we receive a WPD_COMMAND_COMMON_GET_OBJECT_IDS_FROM_PERSISTENT_UNIQUE_IDS * command. * * The parameters sent to us are: * - WPD_PROPERTY_COMMON_PERSISTENT_UNIQUE_IDS: Contains an IPortableDevicePropVariantCollection of VT_LPWSTR, * indicating the PersistentUniqueIDs. * * The driver should: * - Iterate through the PersistentUniqueIDs, and convert to a currently valid object id. * This object ID list should be returned as an IPortableDevicePropVariantCollection of VT_LPWSTR * in WPD_PROPERTY_COMMON_OBJECT_IDS. * Order is implicit, i.e. the first element in the Persistent Unique ID list corresponds to the * to the first element of the ObjectID list and so on. * * For those elements where an existing ObjectID could not be found (e.g. the * object is no longer present on the device), the element will contain the * empty string (L""). */ HRESULT WpdBaseDriver::OnGetObjectIDsFromPersistentUniqueIDs( _In_ IPortableDeviceValues* pParams, _In_ IPortableDeviceValues* pResults) { HRESULT hr = S_OK; DWORD dwCount = 0; CComPtr<IPortableDevicePropVariantCollection> pPersistentIDs; CComPtr<IPortableDevicePropVariantCollection> pObjectIDs; if((pParams == NULL) || (pResults == NULL)) { hr = E_POINTER; CHECK_HR(hr, "Cannot have NULL parameter"); return hr; } // Get the list of Persistent IDs if (hr == S_OK) { hr = pParams->GetIPortableDevicePropVariantCollectionValue(WPD_PROPERTY_COMMON_PERSISTENT_UNIQUE_IDS, &pPersistentIDs); CHECK_HR(hr, "Failed to get WPD_PROPERTY_COMMON_PERSISTENT_UNIQUE_IDS"); } // Create the collection to hold the ObjectIDs if (hr == S_OK) { hr = CoCreateInstance(CLSID_PortableDevicePropVariantCollection, NULL, CLSCTX_INPROC_SERVER, IID_IPortableDevicePropVariantCollection, (VOID**) &pObjectIDs); CHECK_HR(hr, "Failed to CoCreate CLSID_PortableDevicePropVariantCollection"); } // Iterate through the persistent ID list and add the equivalent object ID for each element. if (hr == S_OK) { hr = pPersistentIDs->GetCount(&dwCount); CHECK_HR(hr, "Failed to get count from persistent ID collection"); if (hr == S_OK) { DWORD dwIndex = 0; PROPVARIANT pvPersistentID = {0}; PROPVARIANT pvObjectID = {0}; PropVariantInit(&pvPersistentID); PropVariantInit(&pvObjectID); for(dwIndex = 0; dwIndex < dwCount; dwIndex++) { pvObjectID.vt = VT_LPWSTR; hr = pPersistentIDs->GetAt(dwIndex, &pvPersistentID); CHECK_HR(hr, "Failed to get persistent ID at index %d", dwIndex); // Since our persistent unique identifier are identical to our object // identifiers, we just return it back to the caller. if (hr == S_OK) { pvObjectID.pwszVal = AtlAllocTaskWideString(pvPersistentID.pwszVal); } if (hr == S_OK) { hr = pObjectIDs->Add(&pvObjectID); CHECK_HR(hr, "Failed to add next Object ID"); } PropVariantClear(&pvPersistentID); PropVariantClear(&pvObjectID); if(FAILED(hr)) { break; } } } } if (hr == S_OK) { hr = pResults->SetIPortableDevicePropVariantCollectionValue(WPD_PROPERTY_COMMON_OBJECT_IDS, pObjectIDs); CHECK_HR(hr, "Failed to set WPD_PROPERTY_COMMON_OBJECT_IDS"); } return hr; }
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