Webbrowse取消默认文件替换功能，并获取拖放文件路径列表

 

#include "StdAfx.h"
#pragma once
#include "oleidl.h"
class IDropTargetImpl :
	public IDropTarget
{
public:
	IDropTargetImpl(void)
	{
		m_def=0;
	}
	~IDropTargetImpl(void)
	{

	}
	HRESULT STDMETHODCALLTYPE QueryInterface( 
		REFIID riid,
		void** ppvObject)
	{
		if(!ppvObject)return E_POINTER;
		if (riid==IID_IUnknown||riid==IID_IDropTarget)
		{
			*ppvObject=static_cast<IDropTarget*>(this);
		}
		else
			return (*ppvObject=0),E_NOINTERFACE;
		((IUnknown*)*ppvObject)->AddRef();
		return S_OK;

	}

	ULONG STDMETHODCALLTYPE AddRef( void)
	{
		return ++m_def;
	}

	ULONG STDMETHODCALLTYPE Release( void) 
	{
		ULONG Temp=--m_def;
		if (m_def==0)
		{
			delete this;
		}
		return Temp;
	}
	HRESULT STDMETHODCALLTYPE DragEnter( 
		/* [unique][in] */ IDataObject *pDataObj,
		/* [in] */ DWORD grfKeyState,
		/* [in] */ POINTL pt,
		/* [out][in] */ DWORD *pdwEffect)
	{

		/*FORMATETC cFmt = {(CLIPFORMAT) CF_TEXT, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL};

		STGMEDIUM stgMedium;

		HRESULT  hr = pDataObj->GetData(&cFmt, &stgMedium);

		if (S_OK != hr)
		{
		return E_FAIL;
		}*/

		return S_OK;
	}

	HRESULT STDMETHODCALLTYPE DragOver( 
		/* [in] */ DWORD grfKeyState,
		/* [in] */ POINTL pt,
		/* [out][in] */ DWORD *pdwEffect) 
	{
		return S_OK;
	}

	HRESULT STDMETHODCALLTYPE DragLeave( void) 
	{
		return S_OK;
	}

	HRESULT STDMETHODCALLTYPE Drop( 
		/* [unique][in] */ IDataObject *pDataObj,
		/* [in] */ DWORD grfKeyState,
		/* [in] */ POINTL pt,
		/* [out][in] */ DWORD *pdwEffect)
	{
		FORMATETC cFmt = {(CLIPFORMAT) CF_HDROP, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL};
		GetDragData(pDataObj,cFmt);
		return S_OK;
	}

	BOOL ProcessDrop(HDROP hDrop)
	{
		UINT iFiles,ich =0;
		TCHAR Buffer[MAX_PATH] = {0};
		memset(&iFiles,0xff,sizeof(iFiles));
		CString strFilePath;
		int Count = ::DragQueryFile(hDrop,iFiles,Buffer,0); //Get the Drag _Files Number.
		if(Count)
		{
			for (int i=0;i<Count;i++)
			{
				if(::DragQueryFile(hDrop,i,Buffer,sizeof(Buffer)))
				{
					strFilePath = Buffer;//获取了路径做相应处理
					memset(Buffer,0,sizeof(Buffer) );
				}
			}
		}
		::DragFinish(hDrop);
		return true; 
	}

	BOOL GetDragData(IDataObject *pDataObject,FORMATETC cFmt)
	{
		HRESULT ret=S_OK;
		STGMEDIUM stgMedium;
		ret = pDataObject->GetData(&cFmt, &stgMedium);//GetData(CF_TEXT, &stgMedium);

		if (FAILED(ret))
		{
			return FALSE;
		}

		if (stgMedium.pUnkForRelease != NULL)
		{
			return FALSE;
		}

		switch (stgMedium.tymed)
		{
		case TYMED_HGLOBAL:
			{
				ProcessDrop((HDROP)stgMedium.hGlobal);
				return true;
				break;
			}

		default:
			{
				::ReleaseStgMedium(&stgMedium);
			}
			break;
		}
		return false;
	}
protected:
	ULONG m_def;
};

/////////////////////////////////////////////////////////////////////////////////////////////////

class IHandlerImpl :
	public IDocHostUIHandler
{
public:
	IHandlerImpl(void)
	{
		m_def=0;
	}
	~IHandlerImpl(void)
	{

	}

	virtual HRESULT STDMETHODCALLTYPE ShowContextMenu( 
		/* [in] */ DWORD dwID,
		/* [in] */ POINT *ppt,
		/* [in] */ IUnknown *pcmdtReserved,
		/* [in] */ IDispatch *pdispReserved) 
	{
		//    ATLTRACE("%d,%d	",ppt->x,ppt->y);
		return S_FALSE;
	}

	virtual HRESULT STDMETHODCALLTYPE GetHostInfo( 
		/* [out][in] */ DOCHOSTUIINFO *pInfo) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE ShowUI( 
		/* [in] */ DWORD dwID,
		/* [in] */ IOleInPlaceActiveObject *pActiveObject,
		/* [in] */ IOleCommandTarget *pCommandTarget,
		/* [in] */ IOleInPlaceFrame *pFrame,
		/* [in] */ IOleInPlaceUIWindow *pDoc) 
	{

		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE HideUI( void) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE UpdateUI( void)
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE EnableModeless( 
		/* [in] */ BOOL fEnable) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE OnDocWindowActivate( 
		/* [in] */ BOOL fActivate) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE OnFrameWindowActivate( 
		/* [in] */ BOOL fActivate)
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE ResizeBorder( 
		/* [in] */ LPCRECT prcBorder,
		/* [in] */ IOleInPlaceUIWindow *pUIWindow,
		/* [in] */ BOOL fRameWindow) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE TranslateAccelerator( 
		/* [in] */ LPMSG lpMsg,
		/* [in] */ const GUID *pguidCmdGroup,
		/* [in] */ DWORD nCmdID) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE GetOptionKeyPath( 
		/* [out] */ LPOLESTR *pchKey,
		/* [in] */ DWORD dw) 
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE GetDropTarget( 
		/* [in] */ IDropTarget *pDropTarget,
		/* [out] */ IDropTarget **ppDropTarget) 
	{
		IDropTarget *pDrag = new IDropTargetImpl;
		*ppDropTarget = pDrag;
		((IUnknown*)*ppDropTarget)->AddRef();
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE GetExternal( 
		/* [out] */ IDispatch **ppDispatch)
	{
		return S_OK;
	}

	virtual HRESULT STDMETHODCALLTYPE TranslateUrl( 
		/* [in] */ DWORD dwTranslate,
		/* [in] */ OLECHAR *pchURLIn,
		/* [out] */ OLECHAR **ppchURLOut) 
	{
		return S_OK;
	}
	virtual HRESULT STDMETHODCALLTYPE FilterDataObject( 
		/* [in] */ IDataObject *pDO,
		/* [out] */ IDataObject **ppDORet) 
	{
		return S_FALSE;
	}


	HRESULT STDMETHODCALLTYPE QueryInterface( 
		REFIID riid,
		void** ppvObject)
	{

		return S_OK;

	}

	ULONG STDMETHODCALLTYPE AddRef( void)
	{
		return ++m_def;
	}

	ULONG STDMETHODCALLTYPE Release( void) 
	{
		ULONG Temp=--m_def;
		if (m_def==0)
		{
			delete this;
		}
		return Temp;
	}

protected:
	ULONG m_def;
};

真正处理拖放的是IDropTarget，使用方法：替换默认的文件拖放，代码为

CComPtr<IHTMLDocument2> spDoc;                  
	m_HtmlEditCtrl.GetDHtmlDocument(&spDoc);  

	CComPtr<ICustomDoc> spCustomDoc;
	spDoc->QueryInterface(IID_ICustomDoc, (void **)&spCustomDoc);  

	CComPtr<IDocHostUIHandler> spDocHostUIHandler;   
	spCustomDoc->QueryInterface(IID_IDocHostUIHandler, (void **)&spDocHostUIHandler);  

	IDocHostUIHandler* myDocHandler = new IHandlerImpl;
	HRESULT r = spCustomDoc->SetUIHandler(myDocHandler);