COM开发
内容
Win32 SDK和MFC介绍
MFC对COM的支持
用MFC开发COM组件
ATL对COM的支持
用ATL开发COM组件
布置作业
Win32 SDK： Windows程序结构
入口函数WinMain
应用初始化
主窗口的创建及显示
消息分发循环
程序结束处理
Win32 SDK对COM的支持
Win32 SDK包括COM库函数的支持
利用宏描述接口
DECLARE_INTERFACE_(IClassFactory, IUnknown)
{
STDMETHOD(QueryInterface) (THIS_
REFIID riid,
LPVOID FAR* ppvObj) PURE;
STDMETHOD_(ULONG,AddRef) (THIS) PURE;
STDMETHOD_(ULONG,Release) (THIS) PURE;
STDMETHOD(CreateInstance) (THIS_
LPUNKNOWN pUnkOuter,
REFIID riid,
LPVOID FAR* ppvObject) PURE;
STDMETHOD(LockServer)(THIS_
BOOL fLock) PURE;
};
VC提供的用于描述接口的宏
MFC基础
应用类
– AfxGetApp
– CWinApp::InitInstance
– CWinApp::ExitInstance
– CWinApp::OnIdle
– CWinApp::Run
– CWnd *m_pMainWnd
窗口类
– AfxGetMainWnd
MFC的消息处理机制
——消息映射表
在CWnd派生类定义中加入声明：
DECLARE_MESSAGE_MAP()
在类的实现文件中加入表和表项的定义：
BEGIN_MESSAGE_MAP(theClass, baseClass)
......
END_MESSAGE_MAP
消息映射表示例
BEGIN_MESSAGE_MAP(theClass, baseClass)
//{{AFX_MSG_MAP(theClass)
ON_WM_SETFOCUS()
ON_WM_CREATE()
ON_WM_DESTROY()
ON_WM_CLOSE()
ON_WM_SIZE()
ON_MESSAGE(WM_COMMANDHELP, OnCommandHelp)
ON_MESSAGE(WM_HELPHITTEST, OnHelpHitTest)
ON_UPDATE_COMMAND_UI(ID_VIEW_STATUS_BAR,
OnUpdateControlBarMenu)
ON_NOTIFY_EX_RANGE(TTN_NEEDTEXTW, 0, 0xFFFF,
OnToolTipText)
//}}AFX_MSG_MAP
END_MESSAGE_MAP
MFC应用类型
常规应用：MDI应用、SDI应用、基于对话框
程序
DLL应用：静态连接MFC库的正规DLL、动态
连接MFC库的正规DLL、MFC扩展DLL
其他应用：
– 支持OLE服务或者包容器的SDI应用
– 支持OLE服务或者包容器的MDI应用
– 支持自动化(Automation)服务的SDI或者MDI程序
– ActiveX控制应用(OCX应用)
MFC库结构
MFC对COM应用的支持
用嵌套类实现COM接口
class CDictionary
{
…… //构造函数和析构函数
HRESULT __stdcall QueryInterface(REFIID iid, void** ppvObj);
ULONG __stdcall AddRef();
ULONG __stdcall Release();
class XDictionaryObj : public IDictionary {
public:
CDictionary * m_pParent;
virtual HRESULT __stdcall QueryInterface(REFIID iid, void** ppvObj);
virtual ULONG __stdcall AddRef();
virtual ULONG __stdcall Release();
virtual BOOL __stdcall Initialize();
…...
virtual void __stdcall FreeLibrary();
} m_dictionaryObj; 未完
用嵌套类实现COM接口(续一)
class XSpellCheckObj : public ISpellCheck {
public:
CDictionary * m_pParent;
virtual HRESULT __stdcall QueryInterface(REFIID iid, void**
ppvObj);
virtual ULONG __stdcall AddRef();
virtual ULONG __stdcall Release();
virtual BOOL __stdcall CheckWord (String word, String *);
} m_spellCheckObj;
private :
struct DictWord *m_pData;
char *m_DictFilename[128];
int m_Ref ;
int m_nWordNumber, m_nStructNumber;
};
续
用嵌套类实现COM接口(续二)
CDictionary::CDictionary()
{
....... // Initializtion
m_dictionaryObj. m_pParent = this;
m_spellCheckObj. m_pParent = this;
}
用嵌套类实现COM接口(续三)
HRESULT CDictionary::QueryInterface(const IID& iid, void **ppvObj)
{
if (iid == IID_IUnknown || iid == IID_Dictionary) {
*ppvObj = &m_dictionaryObj;
AddRef();
return S_OK;
} else if (iid == IID_SpellCheck) {
*ppvObj = &m_spellCheckObj;
AddRef();
return S_OK;
}
*ppv = NULL;
return E_NOINTERFACE ;
}
用嵌套类实现COM接口(续四)
ULONG CDictionary::XDictionaryObj::QueryInterface(const IID& iid,
void **ppvObj)
{
return m_pParent->QueryInterface(iid, ppvObj);
}
ULONG CDictionary::XDictionaryObj::AddRef()
{
return m_pParent->AddRef();
}
ULONG CDictionary::XDictionaryObj::Release ()
{
return m_pParent->Release ();
}
“用嵌套类实现COM接口”原理
m_pData
m_DictFilename[128]
m_Ref
m_nWordNumber
m_nStructNumber
QueryInterface
AddRef
Release
…….
m_dictionaryObj
m_spellCheckObj
QueryInterface
AddRef
Release
……
QueryInterface
AddRef
Release
……
Vtable for IDictionary
Vtable for ISpellCheck
CDictionary
vptr
vptr
CDictionary的非虚函数
MFC：接口映射表
CCmdTarget类
CCmdTarget::m_dwRef为引用计数
接口映射表与消息映射表非常类似
接口映射表：记录了CCmdTarget类中
每一个嵌套类的接口ID以及接口vtable
与父类this指针之间的偏移量
offsetof宏：成员类与父类之间的偏移值
DECLARE_INTERFACE_MAP
#define DECLARE_INTERFACE_MAP() \
private: \
static const AFX_INTERFACEMAP_ENTRY _interfaceEntries[]; \
protected: \
static AFX_DATA const AFX_INTERFACEMAP interfaceMap; \
static const AFX_INTERFACEMAP* PASCAL _GetBaseInterfaceMap(); \
virtual const AFX_INTERFACEMAP* GetInterfaceMap() const; \
struct AFX_INTERFACEMAP_ENTRY
{
const void* piid;
size_t nOffset;
};
struct AFX_INTERFACEMAP
{
#ifdef _AFXDLL
const AFX_INTERFACEMAP* (PASCAL*
pfnGetBaseMap)();
#else
const AFX_INTERFACEMAP* pBaseMap;
#endif
const AFX_INTERFACEMAP_ENTRY* pEntry;
};
接口映射表定义
BEGIN_INTERFACE_MAP(CDictionary, CCmdTarget)
INTERFACE_PART(CDictionary, IID_IDictionary, Dictionary)
INTERFACE_PART(CDictionary, IID_ISpellCheck, SpellCheck)
END_INTERFACE_MAP()
接口映射表的宏定义
#define BEGIN_INTERFACE_MAP(theClass, theBase) \
const AFX_INTERFACEMAP* PASCAL theClass::_GetBaseInterfaceMap() \
{ return &theBase::interfaceMap; } \
const AFX_INTERFACEMAP* theClass::GetInterfaceMap() const \
{ return &theClass::interfaceMap; } \
AFX_COMDAT const AFX_DATADEF \
AFX_INTERFACEMAP theClass::interfaceMap = \
{ &theClass::_GetBaseInterfaceMap, &theClass::_interfaceEntries[0], }; \
AFX_COMDAT const AFX_DATADEF
AFX_INTERFACEMAP_ENTRY theClass::_interfaceEntries[] = \
{ \
#define INTERFACE_PART(theClass, iid, localClass) \
{ &iid, offsetof(theClass, m_x##localClass) }, \
#define END_INTERFACE_MAP() \
{ NULL, (size_t)-1 } \
}; \
MFC版本的字典对象类定义
class CDictionary : public CCmdTarget
{
DECLARE_DYNCREATE(CDictionary)
CDictionary(); // protected constructor used by dynamic creation
DECLARE_INTERFACE_MAP()
......
// IDictionary
BEGIN_INTERFACE_PART(Dictionary, IDictionary)
INIT_INTERFACE_PART(CDictionary, Dictionary)
STDMETHOD_(BOOL, Initialize)();
……
STDMETHOD_(void, FreeLibrary)();
END_INTERFACE_PART_STATIC(Dictionary)
// ISpellCheck
BEGIN_INTERFACE_PART(SpellCheck, ISpellCheck)
INIT_INTERFACE_PART(CDictionary, SpellCheck)
STDMETHOD_(BOOL, CheckWord)(LPOLESTR, LPOLESTR *);
END_INTERFACE_PART_STATIC(SpellCheck)
};
MFC版本的字典对象类实现
STDMETHODIMP_(ULONG) CDictionary::XDictionary::AddRef()
{
METHOD_PROLOGUE_EX_(CDictionary, Dictionary)
return pThis->ExternalAddRef();
}
METHOD_PROLOGUE_EX_宏定义：
#define METHOD_PROLOGUE_EX(theClass, localClass) \
theClass* pThis = ((theClass*)((BYTE*)this - m_nOffset)); \
AFX_MANAGE_STATE(pThis->m_pModuleState) \
pThis; // avoid warning from compiler \
CCmdTarget类实现IUnknown
public:
// data used when CCmdTarget is made OLE aware
long m_dwRef;
LPUNKNOWN m_pOuterUnknown; // external controlling unknown if
!= NULL
DWORD m_xInnerUnknown; // place-holder for inner controlling
unknown
public:
// advanced operations
void EnableAggregation(); // call to enable aggregation
void ExternalDisconnect(); // forcibly disconnect
LPUNKNOWN GetControllingUnknown();
// get controlling IUnknown for aggregate creation
CCmdTarget类实现IUnknown(续)
public:
// these versions do not delegate to m_pOuterUnknown
DWORD InternalQueryInterface(const void*, LPVOID* ppvObj);
DWORD InternalAddRef();
DWORD InternalRelease();
// these versions delegate to m_pOuterUnknown
DWORD ExternalQueryInterface(const void*, LPVOID* ppvObj);
DWORD ExternalAddRef();
DWORD ExternalRelease();
CCmdTarget中QueryInterface实现
DWORD CCmdTarget::InternalQueryInterface(const void* iid, LPVOID*
ppvObj)
{
// check local interfaces
if ((*ppvObj = GetInterface(iid)) != NULL) {
// interface was found -- add a reference
ExternalAddRef();
return S_OK;
}
// check aggregates
if ((*ppvObj = QueryAggregates(iid)) != NULL)
return S_OK;
// interface ID not found, fail the call
return (DWORD)E_NOINTERFACE;
}
CCmdTarget中ExternalXXX成员实现
DWORD CCmdTarget::ExternalAddRef()
{
// delegate to controlling unknown if aggregated
if (m_pOuterUnknown != NULL)
return m_pOuterUnknown->AddRef();
return InternalAddRef();
}
DWORD CCmdTarget::ExternalRelease() // …...
// QueryInterface that is exported to normal clients
DWORD CCmdTarget::ExternalQueryInterface(const void* iid, LPVOID* ppvObj)
{
// delegate to controlling unknown if aggregated
if (m_pOuterUnknown != NULL)
return m_pOuterUnknown->QueryInterface(*(IID*)iid, ppvObj);
return InternalQueryInterface(iid, ppvObj);
}
嵌套类内部实现IUnknown的成员函数
STDMETHODIMP_(ULONG) CDictionary::XDictionary::QueryInterface
(
const void* iid, LPVOID* ppvObj)
{
METHOD_PROLOGUE_EX_(CDictionary, Dictionary)
return pThis->ExternalQueryInterface (iid, ppvObj);
}
COM引出函数和类厂实现
在AppWizard中选中“Automation”检查框
STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID* ppv)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState());
return AfxDllGetClassObject(rclsid, riid, ppv);
}
STDAPI DllCanUnloadNow(void)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState());
return AfxDllCanUnloadNow();
}
// by exporting DllRegisterServer, you can use
STDAPI DllRegisterServer(void)
{
AFX_MANAGE_STATE(AfxGetStaticModuleState());
COleObjectFactory::UpdateRegistryAll();
return S_OK;
}
COleObjectFactory
通用的类厂，实现了IClassFactory2接口
COleObjectFactory的主要信息是对象的CLSID和对
象的类型信息。
它利用MFC的动态对象创建机制：
– DECLARE_DYNCREATE
对象方面的支持：
– DECLARE_OLECREATE(...)，定义如下
#define DECLARE_OLECREATE(class_name) \
public: \
static AFX_DATA COleObjectFactory factory; \
static AFX_DATA const GUID guid; \
MFC中组件对象的创建支持
DECLARE_OLECREATE(...)
IMPLEMENT_OLECREATE
#define IMPLEMENT_OLECREATE(class_name, external_name, l, w1, w2, b1, b2, b3, b4, b5,
b6, b7, b8) \
AFX_DATADEF COleObjectFactory class_name::factory(class_name::guid, \
RUNTIME_CLASS(class_name), FALSE, _T(external_name)); \
AFX_COMDAT const AFX_DATADEF GUID class_name::guid = \
{ l, w1, w2, { b1, b2, b3, b4, b5, b6, b7, b8 } }; \
状态结构：AFX_MODULE_STATE，除了一些基本的全局信息，还
包括一个类厂表。
DllGetClassObject-〉AfxDllGetClassObject-〉
AfxGetModuleState进一步得到类厂表
类厂对象的构造函数和析构函数维护类厂表
用MFC开发COM应用
利用AppWizard创建COM程序工程框架
利用ClassWizard添加COM对象类
AppWizard创建COM工程(一)
AppWizard创建COM工程(二)
AppWizard创建COM工程(三)
BOOL CDictCompApp::InitInstance()
{
// Register all OLE server (factories) as running.
// This enables the
// OLE libraries to create objects from other applications.
COleObjectFactory::RegisterAll();
return TRUE;
}
ClassWizard添加COM对象类(一)
ClassWizard添加COM对象类(二)
CDictionaryObj声明中加入接口定义
BEGIN_INTERFACE_PART(Dictionary, IDictionary)
INIT_INTERFACE_PART(CDictionary, Dictionary)
STDMETHOD_(BOOL, Initialize)();
STDMETHOD_(BOOL, LoadLibrary)(LPOLESTR);
STDMETHOD_(BOOL, InsertWord)(LPOLESTR, LPOLESTR);
STDMETHOD_(void, DeleteWord)( LPOLESTR);
STDMETHOD_(BOOL, LookupWord)(LPOLESTR, LPOLESTR *);
STDMETHOD_(BOOL, RestoreLibrary)(LPOLESTR);
STDMETHOD_(void, FreeLibrary)();
END_INTERFACE_PART_STATIC(Dictionary)
// ISpellCheck
BEGIN_INTERFACE_PART(SpellCheck, ISpellCheck)
INIT_INTERFACE_PART(CDictionary, SpellCheck)
STDMETHOD_(BOOL, CheckWord)(LPOLESTR, LPOLESTR *);
END_INTERFACE_PART_STATIC(SpellCheck)
DECLARE_INTERFACE_MAP()
CDictionaryObj类实现文件中
加入相应的定义
extern "C" const IID IID_Dictionary =
{ 0x54bf6568, 0x1007, 0x11d1,
{ 0xb0, 0xaa, 0x44, 0x45, 0x53, 0x54, 0x00, 0x00} } ;
extern "C" const IID IID_SpellCheck =
{ 0x54bf6569, 0x1007, 0x11d1,
{ 0xb0, 0xaa, 0x44, 0x45, 0x53, 0x54, 0x00, 0x00} } ;
BEGIN_INTERFACE_MAP(CDictionaryObj, CCmdTarget)
INTERFACE_PART(CDictionaryObj, IID_IDictionary, Dictionary)
INTERFACE_PART(CDictionaryObj, IID_ISpellCheck, SpellCheck)
END_INTERFACE_MAP()
类厂支持
在CDictionaryObj声明中加入：
DECLARE_OLECREATE(CDictionaryObj)
在CDictionaryObj实现文件中加入：
// {54BF6567-1007-11D1-B0AA-444553540000}
IMPLEMENT_OLECREATE(CDictionaryObj,
" ",
0x54bf6567, 0x1007, 0x11d1, 0xb0, 0xaa, 0x44,
0x45, 0x53, 0x54, 0x00, 0x00)
ATL介绍
ATL实现COM的机制完全不同于MFC
使用多继承技术实现多个接口
支持多线程
实现QueryInterface用到了特殊的技术
创建对象机制不同于以往的技术
优化
ATL概况
封装了一些数据类型
– CComBSTR、CComVariant、CComPtr，等
实现COM接口和COM对象
– 接口映射表、对象映射表，等
窗口的支持
– CWindow、CWindowImpl、CDialogImpl，等
其他COM特征的支持
– 永久性支持
– 连接点支持
– 集合对象和枚举器对象
– ActiveX control and container
– 等
CComBSTR
封装了BSTR类型
提供了大量便利的字符串操作
–构造函数
–各种操作符以及一般的字符串操作
–对于流(stream)的支持
在需要BSTR的地方，都可以用
CComBSTR来代替
注意owership
CComVariant
封装了VARIANT属性
提供了常用的操作
–构造函数
–各种操作符以及一般的管理操作
–对于流(stream)的支持
在需要VARIANT的地方，都可以用
CComVARIANT来代替
CComPtr、CComQIPtr
Smart pointer
template<class T> template<class T, const IID* piid = &__uuidof(T)>
class CComPtr class CComQIPtr
{ {
public: public:
T* p; T* p;
… ...
}; };
优点：
– 自动管理AddRef/Release
– 在大多数情况下，可以当作接口指针来使用
注意：禁止调用“->Release”和“-
>AddRef”
CComDispatchDriver
封装了IDispatch接口
除了对接口指针的管理之外，有下面的功能：
– 属性访问函数：
• GetIDOfName/ GetProperty/ PutProperty
• GetPropertyByName/ PutPropertyByName
– 方法访问函数：
• by DISPID：Invoke0/Invoke1/Invoke2/InvokeN
• by Name：Invoke0/Invoke1/Invoke2/InvokeN
– 两个静态函数：
• By DISPID：GetProperty/PutProperty
ATL的类层次
CMyClass
CComObjectRootBase
CComObjectRootEx<TM>IXxxImpl IMyItf1 IMyItf2
CComObject<T>等
CComXxxThreadModel
CComObjectRootBase
ObjectMain
static InternalQueryInterface
OuterAddRef/OuterRelease/OuterQueryInterface
InternalFinalConstructAddRef/
InternalFinalConstructRelease
其他一些静态函数
联合：
union
{
long m_dwRef;
IUnknown* m_pOuterUnknown;
};
ATL对象的线程模型
用到了trait技术
通过编译时刻的类型提供just thread-safe
enough
CComSingleThreadModel
CComMultiThreadModel
CComMultiThreadNoCS
提供了两个静态成员函数和三个typedef
– Increment、Decrement
– AutoCriticalSection、CriticalSection、
ThreadModelNoCS
ATL对象实现引用计数
CComObjectRootEx
– InternalAddRef
– InternalRelease
–作用在匿名联合的m_dwRef成员上
CComObjectRootEx定义了一把锁
–锁的类型为AutoCriticalSection
–对锁的封装ObjectLock，wrapper
用于未被聚合的情况下
ATL对象实现QueryInterface
Table-driven QueryInterface
Interface Map
BEGIN_COM_MAP(class)
COM_INTERFACE_ENTRY(itf)
END_COM_MAP
表中每一项
struct _ATL_INTMAP_ENTRY {
const IID* piid;
DWORD dw;
_ATL_CREATORARGFUNC *pFunc;
};
ATL实现的接口类
IDispatchImpl
IPersistStreamInitImpl
IConnectionPointContainerImpl
举例：
template<class T, const IID* piid, …> class IDispatchImpl : public T
{…};
template <class T> class IConnectionPointContainerImpl : public
IConnectionPointContainer{...};
class CMyObject :
public IDispatchImpl<IMyDispInterface,&IID_IMyDispInterface,...
>,
public IConnectionPointContainerImpl< CMyObject >
{…};
真正的ATL对象类
决定这个COM对象如何被分配，是否被聚合等
区别：
– 线程模型是以每个类为基础的，per-class，可以封装到基类中
– 对象的生命周期和身份标识是以每个对象实例为基础的，per-
object，要延后到最终的派生类做出决定
CComObject类：
– template <class Base> CComObject : public Base {…};
– 支持聚合：class CComAggObject;
– 支持聚合： class CComPolyObject;
– template <class Base> CComObjectCached : public Base {…};
– template <class Base> CComObjectNoLock : public Base {…};
– template <class Base> CComObjectGlobal : public Base {…};
– template <class Base> CComObjectStack : public Base {…};
ATL对象的创建
两个步骤：
– 使用CRT的构造器
– FinalConstruct
对应于FinalConstruct有FinalRelease
举例：
CMyClassFactory::CreateInstance() {
……
CComObject<CMyObject> *pObj = new CComObject<CMyObject>;
…...
pObj->InternalFinalConstructAddRef();
HRESULT hr = FinalConstruct();
pObj->InternalFinalConstructRelease();
……
}
ATL Creators
每个creator类有一个静态CreateInstance函数：
HRESULT WINAPI CreateInstance(void* pv, REFIID riid, LPVOID* ppv);
举例：
template <class T> class CComCreator {
public:
static HRESULT WINAPI CreateInstance(void* pv, REFIID riid, LPVOID*
ppv) {
……
T *pObj = new T(pv);
…...
pObj->InternalFinalConstructAddRef();
HRESULT hr = FinalConstruct();
pObj->InternalFinalConstructRelease();
……
hr = p->QueryInterface(riid, ppv);
……
}
};
ATL Creators(续)
其他的creator类有
– CComCreator2 —— 根据pv参数是否为null从两个对象类中择一
– CComFailCreator —— 假的创建类
在CMyObject类中定义一个类型_CreatorClass，例如
– typedef CComCreator<CComObject<CMyObject>>
_CreatorClass;
CComCoClass定义：
template<class T, const CLSID* pclsid = &CLSID_NULL>
class CComCoClass {
public:
……
template<class Q> static HRESULT CreateInstance(IUnknown*
punkOuter, Q** pp)
{ return T::_CreatorClass::CreateInstance(punkOuter, __uuidof(Q),
(void **)pp); }
……
};
聚合情况下对象结构图
CMyClass
CComObjectRootBase
CComObjectRootEx<TM>IXxxImpl IMyItf1 IMyItf2
CComContainedObject
CComXxxThreadModel
CComAggObject
IUnknown
委托IUnknown
非委托IUnknown
ATL中对象聚合的实现
template <class contained>
class CComAggObject :
public IUnknown,
public CComObjectRootEx<
contained::_ThreadModel::ThreadModelNoCS >
{
public :
STDMETHOD_(ULONG, AddRef)() {…}
STDMETHOD_(ULONG, Release)() {…}
STDMETHOD(QueryInterface)(REFIID iid, void ** ppvObject){…}
……
CComContainedObject<contained> m_contained;
};
非委托IUnknown
委托IUnknown
ATL中对象聚合的实现(续)
template <class Base> //Base must be derived from CComObjectRoot
class CComContainedObject : public Base
{
public:
typedef Base _BaseClass;
CComContainedObject(void* pv) {m_pOuterUnknown =
(IUnknown*)pv;}
STDMETHOD_(ULONG, AddRef)() {return OuterAddRef();}
STDMETHOD_(ULONG, Release)() {return OuterRelease();}
STDMETHOD(QueryInterface)(REFIID iid, void ** ppvObject)
{ …… // 调用 OuterQueryInterface(iid, ppvObject); }
……
IUnknown* GetControllingUnknown() { … }
};
// CComObjectRootBase基类中联合成员m_pOuterUnknown起作用
接口映射表项类型
COM_INTERFACE_ENTRY
COM_INTERFACE_ENTRY_IID(iid, x)
COM_INTERFACE_ENTRY2(x, x2)
COM_INTERFACE_ENTRY2_IID(iid, x, x2)
COM_INTERFACE_ENTRY_FUNC(iid, dw, func)
COM_INTERFACE_ENTRY_FUNC_BLIND(dw, func)
COM_INTERFACE_ENTRY_TEAR_OFF(iid, x)
COM_INTERFACE_ENTRY_CACHED_TEAR_OFF(iid, x, punk)
COM_INTERFACE_ENTRY_AGGREGATE(iid, punk)
COM_INTERFACE_ENTRY_AGGREGATE_BLIND(punk)
COM_INTERFACE_ENTRY_CHAIN(classname)
ATL Servers
功能
– Register and Unregister all class
– exposing class object
– managing server’s lifetime
ATL实现结构
– object map
– CComModule
Object Map
示例
BEGIN_OBJECT_MAP(ObjectMap)
OBJECT_ENTRY(CLSID_DictionaryObj, CDictionaryObj)
OBJECT_ENTRY_NON_CREATEABLE(COtherObj)
END_OBJECT_MAP()
宏定义：
#define BEGIN_OBJECT_MAP(x) static _ATL_OBJMAP_ENTRY x[] = {
#define END_OBJECT_MAP() {NULL, NULL, NULL, NULL, NULL,
NULL, NULL, NULL}};
_ATL_OBJMAP_ENTRY定义
struct _ATL_OBJMAP_ENTRY
{
const CLSID* pclsid;
HRESULT (WINAPI *pfnUpdateRegistry)(BOOL
bRegister);
_ATL_CREATORFUNC* pfnGetClassObject;
_ATL_CREATORFUNC* pfnCreateInstance;
IUnknown* pCF;
DWORD dwRegister;
_ATL_DESCRIPTIONFUNC* pfnGetObjectDescription;
_ATL_CATMAPFUNC* pfnGetCategoryMap;
void (WINAPI *pfnObjectMain)(bool bStarting);
};
OBJECT_ENTRY定义
#define OBJECT_ENTRY(clsid, class) {&clsid,
class::UpdateRegistry,
class::_ClassFactoryCreatorClass::CreateInstanc
e, class::_CreatorClass::CreateInstance, NULL, 0,
class::GetObjectDescription,
class::GetCategoryMap, class::ObjectMain },
#define
OBJECT_ENTRY_NON_CREATEABLE(class)
{&CLSID_NULL, class::UpdateRegistry, NULL,
NULL, NULL, 0, NULL, class::GetCategoryMap,
class::ObjectMain },
类的注册
OBJECT_ENTRY中的class::UpdateRegistry项
– 要求每个类都要提供UpdateRegistry成员
– 宏：
• DECLARE_NO_REGISTRY()
• DECLARE_REGISTRY(class, pid, vpid, nid, flags)
• DECLARE_REGISTRY_RESOURCE(x)
• DECLARE_REGISTRY_RESOURCEID(x)
缺省生成的工程使用资源进行注册
– Registry Script File
类 厂
OBJECT_ENTRY宏包含：
class::_ClassFactoryCreatorClass::CreateInstance
DECLARE_CLASSFACTORY_EX宏定义：
#define DECLARE_CLASSFACTORY_EX(cf) \
typedef CComCreator< CComObjectCached< cf > > \
_ClassFactoryCreatorClass;
#define DECLARE_CLASSFACTORY() \
DECLARE_CLASSFACTORY_EX(CComClassFactory)
CComCoClass定义中包含
DECLARE_CLASSFACTORY()
类实例的创建
OBJECT_ENTRY宏包含：
class::_CreatorClass::CreateInstance
DECLARE_AGGREGATABLE(x)宏定义：
#define DECLARE_AGGREGATABLE(x) public:\
typedef CComCreator2< CComCreator< CComObject< x > >, \
CComCreator< CComAggObject< x > > > _CreatorClass;
CComCoClass定义中包含
DECLARE_AGGREGATABLE(T)
类厂与类实例的连接
类厂的初始化
– in-proc server，DllGetClassObject
– out-of-proc server，RegisterClassObject
把实例创建函数传递给类厂
– CComClassFactory类具有以下成员：
_ATL_CREATORFUNC* m_pfnCreateInstance;
类厂的CreateInstance方法调用
m_pfnCreateInstance
CComModule
全局变量
– ATL inproc server：CComModule _Module;
– ATL local server：CExeModule _Module;
– service-base server：CServiceModule _Module;
Init/Term函数
注册功能
提供全局锁功能
ATL实现窗口类的技术
第一次窗口过程为
ATL窗口类
编译优化
ATL_NO_VTABLE
– 阻止在构造/析构过程中调整vptr，由于纯虚基类的
vtable引用只是被构造/析构函数访问，所以这会导
致链接器优化掉纯虚函数的vptr
_ATL_MIN_CRT
– 不链接标准C/C++运行库
_ATL_DLL
– 动态链接
_ATL_STATIC_REGISTRY
– 静态链接组件注册功能
字典类的ATL对象
class CDictionary :
public CComObjectRootEx<CComSingleThreadModel>,
public CComCoClass<CDictionary, &CLSID_Dictionary>,
public IDictionary,
public ISpellCheck
{
public:
CDictionary() { }
DECLARE_REGISTRY_RESOURCEID(IDR_DICTIONARY)
DECLARE_PROTECT_FINAL_CONSTRUCT()
BEGIN_COM_MAP(CDictionary)
COM_INTERFACE_ENTRY(IDictionary)
COM_INTERFACE_ENTRY(ISpellCheck)
END_COM_MAP()
字典类的ATL对象(续)
public:
// IDictionary
STDMETHOD_(BOOL, Initialize)();
STDMETHOD_(BOOL, LoadLibrary)(LPOLESTR);
STDMETHOD_(BOOL, InsertWord)(LPOLESTR, LPOLESTR);
STDMETHOD_(void, DeleteWord)( LPOLESTR);
STDMETHOD_(BOOL, LookupWord)(LPOLESTR, LPOLESTR *);
STDMETHOD_(BOOL, RestoreLibrary)(LPOLESTR);
STDMETHOD_(void, FreeLibrary)();
// ISpellCheck
STDMETHOD_(BOOL, CheckWord)(LPOLESTR, LPOLESTR *);
private:
……
};
通过 ATL Object Wizard创建对象
通过 ATL Object Wizard设置对象名字
通过 ATL Object Wizard设置对象属性
