C#实现Drag and Drop操作例子

/************************************************************************** File: DataObj.cpp Description: **************************************************************************/ /************************************************************************** #include statements **************************************************************************/ #include "stdafx.h" #include <shlobj.h> #include "DataObj.h" using namespace System::Runtime::InteropServices; namespace ShellUtils { /************************************************************************** CDataObject::CDataObject() **************************************************************************/ CDataObject::CDataObject() { } /************************************************************************** CDataObject::~CDataObject() **************************************************************************/ CDataObject::~CDataObject() { Clear(); } void CDataObject::Clear() { for(Storage::iterator it = m_storage.begin(); it != m_storage.end(); ++it) ReleaseStgMedium(it->lpMed); } /////////////////////////////////////////////////////////////////////////// // // IUnknown Implementation // /************************************************************************** CDataObject::QueryInterface() **************************************************************************/ STDMETHODIMP CDataObject::QueryInterface(REFIID riid, LPVOID *ppvOut) { *ppvOut = NULL; //IUnknown if(IsEqualIID(riid, IID_IUnknown)) { *ppvOut = this; return S_OK; } //IDataObject if(IsEqualIID(riid, IID_IDataObject)) { *ppvOut = (IDataObject*)this; return S_OK; } return E_NOINTERFACE; } /************************************************************************** CDataObject::AddRef() **************************************************************************/ STDMETHODIMP_(ULONG) CDataObject::AddRef(void) { return 2; } /************************************************************************** CDataObject::Release() **************************************************************************/ STDMETHODIMP_(ULONG) CDataObject::Release(void) { return 1; } /////////////////////////////////////////////////////////////////////////// // // IDataObject Implementation // /************************************************************************** CDataObject::GetData() **************************************************************************/ STDMETHODIMP CDataObject::GetData(LPFORMATETC pFE, LPSTGMEDIUM pSM) { if (pFE == NULL || pSM == NULL) return E_INVALIDARG; pSM->hGlobal = NULL; for(Storage::iterator it = m_storage.begin(); it != m_storage.end(); ++it) { if (pFE->tymed & it->lpFmt->tymed && pFE->dwAspect == it->lpFmt->dwAspect && pFE->cfFormat == it->lpFmt->cfFormat) { CopyStgMedium(it->lpMed, pSM); return S_OK; } } return DV_E_FORMATETC; } /************************************************************************** CDataObject::GetDataHere() **************************************************************************/ STDMETHODIMP CDataObject::GetDataHere(LPFORMATETC pFE, LPSTGMEDIUM pSM) { return E_NOTIMPL; } /************************************************************************** CDataObject::QueryGetData() **************************************************************************/ STDMETHODIMP CDataObject::QueryGetData(LPFORMATETC pFE) { if (pFE == NULL) return E_INVALIDARG; //support others if needed DVASPECT_THUMBNAIL //DVASPECT_ICON //DVASPECT_DOCPRINT if (!(DVASPECT_CONTENT & pFE->dwAspect)) return (DV_E_DVASPECT); HRESULT hr = DV_E_TYMED; for(Storage::iterator it = m_storage.begin(); it != m_storage.end(); ++it) { if (pFE->tymed & it->lpFmt->tymed) { if (pFE->cfFormat == it->lpFmt->cfFormat) return S_OK; else hr = DV_E_CLIPFORMAT; } else hr = DV_E_TYMED; } return hr; } /************************************************************************** CDataObject::GetCanonicalFormatEtc() **************************************************************************/ STDMETHODIMP CDataObject::GetCanonicalFormatEtc(LPFORMATETC pFE1, LPFORMATETC pFE2) { return DATA_S_SAMEFORMATETC; } /************************************************************************** CDataObject::SetData() **************************************************************************/ STDMETHODIMP CDataObject::SetData(LPFORMATETC pFE , LPSTGMEDIUM pSM, BOOL fRelease) { if (pFE == NULL || pSM == NULL) return E_INVALIDARG; for(Storage::iterator it = m_storage.begin(); it != m_storage.end(); ++it) { if (pFE->tymed & it->lpFmt->tymed && pFE->dwAspect == it->lpFmt->dwAspect && pFE->cfFormat == it->lpFmt->cfFormat) { m_storage.erase(it); break; } } FORMATETC* fetc=new FORMATETC; STGMEDIUM* pStgMed = new STGMEDIUM; if (fetc == NULL || pStgMed == NULL) return E_OUTOFMEMORY; ZeroMemory(fetc, sizeof(FORMATETC)); ZeroMemory(pStgMed, sizeof(STGMEDIUM)); *fetc = *pFE; if (fRelease) *pStgMed = *pSM; else CopyStgMedium(pSM, pStgMed); DataStorage storage; storage.lpFmt = fetc; storage.lpMed = pStgMed; m_storage.push_back(storage); return S_OK; } /************************************************************************** CDataObject::EnumFormatEtc() **************************************************************************/ STDMETHODIMP CDataObject::EnumFormatEtc(DWORD dwDir, LPENUMFORMATETC *ppEnum) { *ppEnum = NULL; switch(dwDir) { case DATADIR_GET: { *ppEnum = new CEnumFormatEtc(m_storage); if(*ppEnum) return S_OK; break; } default: return OLE_S_USEREG; } return E_OUTOFMEMORY; } /************************************************************************** CDataObject::DAdvise() **************************************************************************/ STDMETHODIMP CDataObject::DAdvise( LPFORMATETC pFE, DWORD advf, LPADVISESINK pAdvSink, LPDWORD pdwConnection) { return E_NOTIMPL; } /************************************************************************** CDataObject::DUnadvise() **************************************************************************/ STDMETHODIMP CDataObject::DUnadvise(DWORD dwConnection) { return E_NOTIMPL; } /************************************************************************** CDataObject::EnumDAdvise() **************************************************************************/ STDMETHODIMP CDataObject::EnumDAdvise(LPENUMSTATDATA *ppenumAdvise) { return OLE_E_ADVISENOTSUPPORTED; } DataObjectEx::DataObjectEx() { _pDataObject = new CDataObject(); } DataObjectEx::~DataObjectEx() { if(_pDataObject) { _pDataObject->Release(); _pDataObject = NULL; } } void DataObjectEx::SetData(Object* o) { DataObject::SetData(o); CacheData(o->GetType()->ToString()); } void DataObjectEx::SetData(String* s, Object* o) { DataObject::SetData(s, o); CacheData(s); } void DataObjectEx::SetData(Type* t, Object* o) { DataObject::SetData(t, o); CacheData(t->ToString()); } void DataObjectEx::SetData(String* s, bool b, Object* o) { DataObject::SetData(s, b, o); CacheData(s); } void _CacheData(LPFORMATETC lpFetc, LPDATAOBJECT pSrc, LPDATAOBJECT pDest) { STGMEDIUM stgMed; if(SUCCEEDED(pSrc->QueryGetData(lpFetc))) { pSrc->GetData(lpFetc, &stgMed);