//---------------------------------------------------------------------------

#include <vcl.h>

#pragma hdrstop

#include "Unit1.h"

#include <OLEIDL.h>

#include <SysUtils.hpp>

#include <ObjIdl.h>

//---------------------------------------------------------------------------

#pragma package(smart_init)

#pragma resource "*.dfm"

TForm1 *Form1;

/*实现IDropTarget COM接口*/

class TOleDragAndDrop :

                        public TObject,

                        public IDropTarget,

                        public IUnknown

{

    private:

        HANDLE d_handle;//注册的窗体句柄

        volatile LONG d_ref; //引用计数器

    public:

    //构造是注册OLEDragDrop

    TOleDragAndDrop(HANDLE handle)

    {

        d_ref = ;

        d_handle = handle;

        RegisterDragDrop(handle,this);

    }

    //必须虚函数，以调用父类的析构

    __fastcall ~TOleDragAndDrop()

    {

        RevokeDragDrop(d_handle);

        //调用父类的析构

    }

    //实现COM要求的QueryInterface

    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, void ** ppvObject)

    {

        HRESULT result=S_OK;

        if (GetInterface(iid,ppvObject))

            result=S_OK;

        else

            result=E_NOINTERFACE;

        return result;

    }

    //实现COM要求的引用计数器

    ULONG STDMETHODCALLTYPE AddRef(void)

    {

        ULONG result = InterlockedDecrement(&d_ref);

        return result;

    }

    //实现COM要求的释放接口

    ULONG STDMETHODCALLTYPE Release(void)

    {

        ULONG result = InterlockedDecrement(&d_ref);

        return result;

    }

    //实现IDropTarget 中的DragOver

    HRESULT STDMETHODCALLTYPE DragOver(DWORD grfKeyState,

        POINTL pt,DWORD *pdwEffect)

    {

        //ShowMessage("drag over");

        return S_OK;

    }

    //实现IDropTarget 中的DragEnter

    HRESULT STDMETHODCALLTYPE DragEnter(IDataObject * pDataObject,

        DWORD grfKeyState, POINTL pt,DWORD * pdwEffect)

    {

        //ShowMessage("drag enter");

        return S_OK;

    }

    //实现IDropTarget 中的DragLeave

    HRESULT STDMETHODCALLTYPE DragLeave(void)

    {

        //ShowMessage("drag leave");

        return S_OK;

    }

    //实现IDropTarget 中的Drop

    HRESULT STDMETHODCALLTYPE Drop(IDataObject *pDataObj,DWORD grfKeyState,

        POINTL pt,DWORD __RPC_FAR *pdwEffect)

    {

        AnsiString retStr;

        FORMATETC format;

        int cf_html = RegisterClipboardFormat("HTML Format");

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

        cFmt.cfFormat = cf_html;

        STGMEDIUM stgMedium;

        pDataObj->GetData(&cFmt, &stgMedium);

        if(stgMedium.tymed == TYMED_HGLOBAL)

        {

            char* html = (char*)GlobalLock(stgMedium.hGlobal);

            ShowMessage(Utf8ToAnsi(html));

            //剩下的就是把<img>。。。</img> 通过XML解析出来

        }

        return S_OK;

    }

};

//---------------------------------------------------------------------------

static TOleDragAndDrop* d_poledragDrop = NULL;

__fastcall TForm1::TForm1(TComponent* Owner)

    : TForm(Owner)

{

    OleInitialize(NULL);

    d_poledragDrop = new TOleDragAndDrop(Memo1->Handle);

}

//---------------------------------------------------------------------------

//---------------------------------------------------------------------------

void __fastcall TForm1::FormDestroy(TObject *Sender)

{

    delete d_poledragDrop;

    d_poledragDrop = NULL;

    OleUninitialize();

}

//---------------------------------------------------------------------------