text.cpp

VC.Net教程,选的较好的例子.

// Text.cpp : 实现文件
//
#include "stdafx.h"
#include "PersistText.h"
#include "Text.h"


// CText

IMPLEMENT_DYNCREATE(CText, CCmdTarget)
CText::CText()
: m_pchText(NULL)
{
	EnableAutomation();
	
	// 为了使应用程序在 OLE 自动化对象处于活动状态时保持
	//	运行，构造函数调用 AfxOleLockApp。
	
	AfxOleLockApp();
}

CText::~CText()
{
	// 为了在用 OLE 自动化创建所有对象后终止应用程序，
	// 	析构函数调用 AfxOleUnlockApp。
	
	AfxOleUnlockApp();
}


void CText::OnFinalRelease()
{
	// 当释放自动化对象的最后一个引用
	//时调用 OnFinalRelease。基类将自动
	//删除该对象。请在调用基类之前添加
	//对象所需的其他清理。

	CCmdTarget::OnFinalRelease();
}


BEGIN_MESSAGE_MAP(CText, CCmdTarget)
END_MESSAGE_MAP()


BEGIN_DISPATCH_MAP(CText, CCmdTarget)
	DISP_PROPERTY_EX(CText, "Text", GetText, SetText, VT_VARIANT)
END_DISPATCH_MAP()

// 注意：我们添加 IID_IText 支持
//以支持来自 VBA 的类型安全绑定。此 IID 必须同附加到 .IDL 文件中的
//调度接口的 GUID 匹配。

// {F676D9C6-9630-401F-81AB-90E356EAEE16}
static const IID IID_IText =
{ 0xF676D9C6, 0x9630, 0x401F, { 0x81, 0xAB, 0x90, 0xE3, 0x56, 0xEA, 0xEE, 0x16 } };

BEGIN_INTERFACE_MAP(CText, CCmdTarget)
	INTERFACE_PART(CText, IID_IText, Dispatch)
END_INTERFACE_MAP()

// {8E6ED099-B0A5-484A-A183-6A65700BEDC8}
IMPLEMENT_OLECREATE_FLAGS(CText, "PersistText.Text", afxRegApartmentThreading, 0x8e6ed099, 0xb0a5, 0x484a, 0xa1, 0x83, 0x6a, 0x65, 0x70, 0xb, 0xed, 0xc8)


// CText 消息处理程序
VARIANT CText::GetText() 
{
	return COleVariant(m_pchText).Detach();
}

void CText::SetText(const VARIANT FAR& newValue) 
{
	CString strTemp;
	ASSERT(newValue.vt == VT_BSTR);
	if(m_pchText != NULL) {
		delete [] m_pchText;
	}
	strTemp = newValue.bstrVal; // converts to narrow chars
	m_pchText = new char[strTemp.GetLength() + 1];
	strcpy(m_pchText, strTemp);
}

STDMETHODIMP_(ULONG) CText::XPersistStream::AddRef()
{
	METHOD_PROLOGUE(CText, PersistStream)
	return (ULONG) pThis->ExternalAddRef();
}

STDMETHODIMP_(ULONG) CText::XPersistStream::Release()
{
	METHOD_PROLOGUE(CText, PersistStream)
	return (ULONG) pThis->ExternalRelease();
}

STDMETHODIMP CText::XPersistStream::QueryInterface(REFIID iid,
			void FAR* FAR* ppvObj)
{
	METHOD_PROLOGUE(CText, PersistStream)
	// ExternalQueryInterface looks up iid in the macro-generated tables
	return (HRESULT) pThis->ExternalQueryInterface(&iid, ppvObj);
}
/////////////////////////////////////////////////////////////////////////////

STDMETHODIMP CText::XPersistStream::GetClassID(LPCLSID lpClassID)
{
	TRACE("Entering CText::XPersistStream::GetClassID\n");
	METHOD_PROLOGUE(CText, PersistStream)
	ASSERT_VALID(pThis);

	*lpClassID = CText::guid;
	return NOERROR;
}

STDMETHODIMP CText::XPersistStream::IsDirty()
{
	TRACE("Entering CText::XPersistStream::IsDirty\n");
	METHOD_PROLOGUE(CText, PersistStream)
	ASSERT_VALID(pThis);

	return NOERROR;
}

STDMETHODIMP CText::XPersistStream::Load(LPSTREAM pStm)
{
	ULONG nLength;
    STATSTG statstg;
	
	METHOD_PROLOGUE(CText, PersistStream)
	ASSERT_VALID(pThis);
	if(pThis->m_pchText != NULL) {
		delete [] pThis->m_pchText;
	}
	// don't need to free statstg.pwcsName because of NONAME flag
	VERIFY(pStm->Stat(&statstg, STATFLAG_NONAME) == NOERROR);
	int nSize = statstg.cbSize.LowPart; // assume < 4 GB
	if(nSize > 0) {
		pThis->m_pchText = new char[nSize];
		pStm->Read(pThis->m_pchText, nSize, &nLength);
	}
	return NOERROR;
}

STDMETHODIMP CText::XPersistStream::Save(LPSTREAM pStm, BOOL fClearDirty)
{
	METHOD_PROLOGUE(CText, PersistStream)
	ASSERT_VALID(pThis);
	int nSize = strlen(pThis->m_pchText) + 1;
	pStm->Write(pThis->m_pchText, nSize, NULL);
	return NOERROR;
}

STDMETHODIMP CText::XPersistStream::GetSizeMax(ULARGE_INTEGER FAR* pcbSize)
{
	TRACE("Entering CText::XPersistStream::GetSizeMax\n");
	METHOD_PROLOGUE(CText, PersistStream)
	ASSERT_VALID(pThis);
	pcbSize->LowPart = strlen(pThis->m_pchText) + 1;
	pcbSize->HighPart = 0; // assume < 4 GB
	return NOERROR;
}