自学教程：C++ Callback函数代码示例

// --------------------------------------------------------------------------//  CNSmlDmAOAdapter::FetchLeafObjectSizeL//  Fetches leaf object size.// -------------------------------------------------------------------------void CNSmlDmAOAdapter::FetchLeafObjectSizeL( const TDesC8& aURI,                                              const TDesC8& aLUID,									         const TDesC8& /* aType */, 									         TInt aResultsRef,									         TInt aStatusRef )    {    LOGSTRING( "CNSmlDmAOAdapter::FetchLeafObjectSizeL: Start" );    LOGSTRING3( "/tFetchLeafObjectSizeL  /tURI: %S, /tLUID: %S,",                          &aURI, &aLUID );       CSmlDmAOCommandElement* cmd =     CSmlDmAOCommandElement::NewLC( ETrue,                                    aStatusRef,                                    aResultsRef,                                    CNSmlDmAOAdapter::EGetSizeCmd,                                   LastURISeg( aURI ),                                    KNullDesC8);                                       TInt luid( KDefaultLuid );        if ( aLUID.Length() > 0 )        {        luid = DesToIntL( aLUID );            }                                           iSettingStore->ExecuteCmdL( *cmd, luid );        LOGSTRING2( "/tCmd executed with status: %d ",                           cmd->Status() );    // if executed get status    if ( cmd->Executed() )         {        Callback().SetStatusL( aStatusRef, cmd->Status() );                    // if successful get results        if ( cmd->Status() == CSmlDmAdapter::EOk )            {            LOGSTRING2( "/tCmd executed with result: %S ",                                   cmd->Data() );            CBufBase* result = CBufFlat::NewL( cmd->Data()->Size() );            CleanupStack::PushL( result );            result->InsertL( 0, *cmd->Data() );            Callback().SetResultsL( aResultsRef, *result, KNullDesC8 );            CleanupStack::PopAndDestroy( result );            }        }    else        {        // failed to execute command        Callback().SetStatusL( aStatusRef, CSmlDmAdapter::EError );        }        CleanupStack::PopAndDestroy( cmd );            LOGSTRING( "CNSmlDmAOAdapter::FetchLeafObjectSizeL: End" );    }

CVkOptionFeedsForm::CVkOptionFeedsForm(CVkProto *proto):	CVkDlgBase(proto, IDD_OPT_FEEDS, false),	m_cbNewsEnabled(this, IDC_NEWS_ENBL),	m_edtNewsInterval(this, IDC_ED_INT_NEWS),	m_spNewsInterval(this, IDC_SPIN_INT_NEWS),	m_cbNotificationsEnabled(this, IDC_NOTIF_ENBL),	m_edtNotificationsInterval(this, IDC_ED_INT_NOTIF),	m_spNotificationsInterval(this, IDC_SPIN_INT_NOTIF),	m_cbNotificationsMarkAsViewed(this, IDC_NOTIF_MARK_VIEWED),	m_cbSpecialContactAlwaysEnabled(this, IDC_SPEC_CONT_ENBL),	m_cbNewsAutoClearHistory(this, IDC_NEWSAUTOCLEAR),	m_cbNewsFilterPosts(this, IDC_F_POSTS),	m_cbNewsFilterPhotos(this, IDC_F_PHOTOS),	m_cbNewsFilterTags(this, IDC_F_TAGS),	m_cbNewsFilterWallPhotos(this, IDC_F_WALLPHOTOS),	m_cbNewsSourceFriends(this, IDC_S_FRIENDS),	m_cbNewsSourceGroups(this, IDC_S_GROUPS),	m_cbNewsSourcePages(this, IDC_S_PAGES),	m_cbNewsSourceFollowing(this, IDC_S_FOLLOWING),	m_cbNewsSourceIncludeBanned(this, IDC_S_BANNED),	m_cbNewsSourceNoReposts(this, IDC_S_NOREPOSTES),	m_cbNotificationFilterComments(this, IDC_N_COMMENTS),	m_cbNotificationFilterLikes(this, IDC_N_LIKES),	m_cbNotificationFilterReposts(this, IDC_N_REPOSTS),	m_cbNotificationFilterMentions(this, IDC_N_MENTIONS),	m_cbNotificationFilterInvites(this, IDC_N_INVITES){	CreateLink(m_cbNewsEnabled, m_proto->m_vkOptions.bNewsEnabled);	CreateLink(m_edtNewsInterval, m_proto->m_vkOptions.iNewsInterval);	CreateLink(m_cbNotificationsEnabled, m_proto->m_vkOptions.bNotificationsEnabled);	CreateLink(m_edtNotificationsInterval, m_proto->m_vkOptions.iNotificationsInterval);	CreateLink(m_cbNotificationsMarkAsViewed, m_proto->m_vkOptions.bNotificationsMarkAsViewed);	CreateLink(m_cbSpecialContactAlwaysEnabled, m_proto->m_vkOptions.bSpecialContactAlwaysEnabled);	CreateLink(m_cbNewsAutoClearHistory, m_proto->m_vkOptions.bNewsAutoClearHistory);	CreateLink(m_cbNewsFilterPosts, m_proto->m_vkOptions.bNewsFilterPosts);	CreateLink(m_cbNewsFilterPhotos, m_proto->m_vkOptions.bNewsFilterPhotos);	CreateLink(m_cbNewsFilterTags, m_proto->m_vkOptions.bNewsFilterTags);	CreateLink(m_cbNewsFilterWallPhotos, m_proto->m_vkOptions.bNewsFilterWallPhotos);	CreateLink(m_cbNewsSourceFriends, m_proto->m_vkOptions.bNewsSourceFriends);	CreateLink(m_cbNewsSourceGroups, m_proto->m_vkOptions.bNewsSourceGroups);	CreateLink(m_cbNewsSourcePages, m_proto->m_vkOptions.bNewsSourcePages);	CreateLink(m_cbNewsSourceFollowing, m_proto->m_vkOptions.bNewsSourceFollowing);	CreateLink(m_cbNewsSourceIncludeBanned, m_proto->m_vkOptions.bNewsSourceIncludeBanned);	CreateLink(m_cbNewsSourceNoReposts, m_proto->m_vkOptions.bNewsSourceNoReposts);	CreateLink(m_cbNotificationFilterComments, m_proto->m_vkOptions.bNotificationFilterComments);	CreateLink(m_cbNotificationFilterLikes, m_proto->m_vkOptions.bNotificationFilterLikes);	CreateLink(m_cbNotificationFilterReposts, m_proto->m_vkOptions.bNotificationFilterReposts);	CreateLink(m_cbNotificationFilterMentions, m_proto->m_vkOptions.bNotificationFilterMentions);	CreateLink(m_cbNotificationFilterInvites, m_proto->m_vkOptions.bNotificationFilterInvites);	m_cbNewsEnabled.OnChange = Callback(this, &CVkOptionFeedsForm::On_cbNewsEnabledChange);	m_cbNotificationsEnabled.OnChange = Callback(this, &CVkOptionFeedsForm::On_cbNotificationsEnabledChange);}

CFacebookGuardDialog::CFacebookGuardDialog(FacebookProto *proto, const char *fb_dtsg)	: CFacebookDlgBase(proto, IDD_GUARD, false),	m_ok(this, IDOK),	m_sms(this, IDC_SEND_SMS),	m_text(this, IDC_TEXT),	m_fb_dtsg(fb_dtsg){	memset(m_code, 0, sizeof(m_code));	m_ok.OnClick = Callback(this, &CFacebookGuardDialog::OnOk);	m_sms.OnClick = Callback(this, &CFacebookGuardDialog::OnSms);}

CJabberDlgBookmarks::CJabberDlgBookmarks(CJabberProto *proto) :	CSuper(proto, IDD_BOOKMARKS, NULL),	m_btnAdd(this,      IDC_ADD,    SKINICON_OTHER_ADDCONTACT, LPGEN("Add")),	m_btnEdit(this,     IDC_EDIT,   SKINICON_OTHER_RENAME,     LPGEN("Edit")),	m_btnRemove(this,   IDC_REMOVE, SKINICON_OTHER_DELETE,     LPGEN("Remove")),	m_lvBookmarks(this, IDC_BM_LIST, true, true){	m_lvBookmarks.OnItemActivate = Callback(this, &CJabberDlgBookmarks::lvBookmarks_OnDoubleClick);	m_btnAdd.OnClick = Callback(this, &CJabberDlgBookmarks::btnAdd_OnClick);	m_btnEdit.OnClick = Callback(this, &CJabberDlgBookmarks::btnEdit_OnClick);	m_btnRemove.OnClick = Callback(this, &CJabberDlgBookmarks::btnRemove_OnClick);}

CVkCaptchaForm::CVkCaptchaForm(CVkProto *proto, CAPTCHA_FORM_PARAMS *param) :	CVkDlgBase(proto, IDD_CAPTCHAFORM, false),	m_instruction(this, IDC_INSTRUCTION),	m_edtValue(this, IDC_VALUE),	m_btnOpenInBrowser(this, IDOPENBROWSER),	m_btnOk(this, IDOK),	m_param(param){	m_btnOpenInBrowser.OnClick = Callback(this, &CVkCaptchaForm::On_btnOpenInBrowser_Click);	m_btnOk.OnClick = Callback(this, &CVkCaptchaForm::On_btnOk_Click);	m_edtValue.OnChange = Callback(this, &CVkCaptchaForm::On_edtValue_Change);}

 void Replace(uint32_t index, T entry) {    if (index < Size())    {       Callback(Buffer_Remove, BufferImpl<T>::at(index));       BufferImpl<T>::at(index) = entry;       Callback(Buffer_Add, entry);    }    else    {       Add(entry);    } }

CLuaOptions::CLuaOptions(int idDialog)	: CDlgBase(g_hInstance, idDialog),	m_popupOnError(this, IDC_POPUPONERROR),	m_popupOnObsolete(this, IDC_POPUPONOBSOLETE),	isScriptListInit(false), m_scripts(this, IDC_SCRIPTS),	m_reload(this, IDC_RELOAD){	CreateLink(m_popupOnError, "PopupOnError", DBVT_BYTE, 1);	CreateLink(m_popupOnObsolete, "PopupOnObsolete", DBVT_BYTE, 1);	m_scripts.OnClick = Callback(this, &CLuaOptions::OnScriptListClick);	m_reload.OnClick = Callback(this, &CLuaOptions::OnReload);}

    auto Accept(ConnectionWrapper *Connection, CallbackFunctor &&Callback)    {        // Accept on streamed socket.        if (Connection->Type == eConnection::STREAMED)        {            sockaddr ClientInfo;            int ClientLength = 0;            void *Socket = (void *)accept((SOCKET)Connection->Handle.Streamed.Socket, &ClientInfo, &ClientLength);            return Callback(Socket, &ClientInfo, ClientLength);        }        return Callback(nullptr, nullptr, 0);    }

boolCamerasChild::RecvFrameSizeChange(const CaptureEngine& capEngine,                                  const int& capId,                                  const int& w, const int& h){  LOG((__PRETTY_FUNCTION__));  MutexAutoLock lock(mCallbackMutex);  if (Callback(capEngine, capId)) {    Callback(capEngine, capId)->FrameSizeChange(w, h, 0);  } else {    LOG(("Frame size change with dead callback"));  }  return true;}

void InputManager::HandleEvent(sf::Event e) {	// check for resize event and recreate view	if(e.Type == sf::Event::Resized) {		Root::get_mutable_instance().ResetView();	}    // check for keyboard event	if(e.Type == sf::Event::KeyPressed or e.Type == sf::Event::KeyReleased) {		for(auto i = mKeyBindings.begin(); i != mKeyBindings.end(); ++i) {			if(i->Key == e.Key.Code or i->UseAnyKey) {				if((i->EventType == KEY_PRESSED and e.Type == sf::Event::KeyPressed) or						(i->EventType == KEY_RELEASED and e.Type == sf::Event::KeyReleased))					i->Callback();			}		}	}    // check for mouse event    if(e.Type == sf::Event::MouseButtonPressed or			e.Type == sf::Event::MouseButtonReleased or			e.Type == sf::Event::MouseMoved or			e.Type == sf::Event::MouseWheelMoved) {        for(auto i = mMouseBindings.begin(); i != mMouseBindings.end(); ++i) {            if((i->EventType == BUTTON_PRESSED and					e.Type == sf::Event::MouseButtonPressed)					and i->Button == e.MouseButton.Button) {                MouseEventArgs a;				a.SetScreenPixel(Vector2D(e.MouseButton.X, e.MouseButton.Y));                i->Callback(a);            } else if((i->EventType == BUTTON_RELEASED and					e.Type == sf::Event::MouseButtonReleased) and 					i->Button == e.MouseButton.Button) {                MouseEventArgs a;				a.SetScreenPixel(Vector2D(e.MouseButton.X, e.MouseButton.Y));                i->Callback(a);			} else if(i->EventType == MOUSE_MOVED and					e.Type == sf::Event::MouseMoved) {                MouseEventArgs a;				a.SetScreenPixel(Vector2D(e.MouseMove.X, e.MouseMove.Y));                i->Callback(a);            } else if(i->EventType == WHEEL_MOVED and					e.Type == sf::Event::MouseWheelMoved) {                MouseEventArgs a;                a.WheelDelta = e.MouseWheel.Delta;				i->Callback(a);            }        }    }}

void CUICustomEdit::Register_callbacks(){	ec().assign_callback( DIK_ESCAPE,      text_editor::ks_free, Callback( this, &CUICustomEdit::press_escape ) );	ec().assign_callback( DIK_RETURN,      text_editor::ks_free, Callback( this, &CUICustomEdit::press_commit ) );	ec().assign_callback( DIK_NUMPADENTER, text_editor::ks_free, Callback( this, &CUICustomEdit::press_commit ) );	ec().assign_callback( DIK_GRAVE,       text_editor::ks_free, Callback( this, &CUICustomEdit::nothing ) );//	ec().assign_callback( DIK_TAB,   text_editor::ks_free,  Callback( this, &CConsole::Find_cmd      ) );//	ec().assign_callback( DIK_TAB,   text_editor::ks_Shift, Callback( this, &CConsole::Find_cmd_back ) );//	ec().assign_callback( DIK_UP,    text_editor::ks_free,  Callback( this, &CConsole::Prev_cmd      ) );//	ec().assign_callback( DIK_DOWN,  text_editor::ks_free,  Callback( this, &CConsole::Next_cmd      ) );//	ec().assign_callback( DIK_TAB,   text_editor::ks_Alt,   Callback( this, &CConsole::GamePause ) );}

LightNode::LightNode(const IEntityClassPtr& eclass) :	EntityNode(eclass),	_light(_entity,		   *this,		   Callback(boost::bind(&scene::Node::transformChanged, this)),		   Callback(boost::bind(&scene::Node::boundsChanged, this)),		   Callback(boost::bind(&LightNode::lightChanged, this))),	_lightCenterInstance(_light.getDoom3Radius().m_centerTransformed, boost::bind(&LightNode::selectedChangedComponent, this, _1)),	_lightTargetInstance(_light.targetTransformed(), boost::bind(&LightNode::selectedChangedComponent, this, _1)),	_lightRightInstance(_light.rightTransformed(), _light.targetTransformed(), boost::bind(&LightNode::selectedChangedComponent, this, _1)),	_lightUpInstance(_light.upTransformed(), _light.targetTransformed(), boost::bind(&LightNode::selectedChangedComponent, this, _1)),	_lightStartInstance(_light.startTransformed(), boost::bind(&LightNode::selectedChangedComponent, this, _1)),	_lightEndInstance(_light.endTransformed(), boost::bind(&LightNode::selectedChangedComponent, this, _1)),	m_dragPlanes(boost::bind(&LightNode::selectedChangedComponent, this, _1)){}

void ForwardType::Fire(py::list argumentsList) {	for(std::list<ForwardFunction>::iterator it = Functions.begin();		it != Functions.end(); it++) {		ForwardFunction fwdFunction = *it;		PyThreadState *oldThreadState = PyThreadState_Get();		PyThreadState_Swap(fwdFunction.ThreadState);		py::object returnValue = py::object(true);		try {			py::object returnValue = fwdFunction.PythonFunction(*py::tuple(argumentsList));		}		catch(const py::error_already_set &) {			PyErr_Print();		}		PyThreadState_Swap(oldThreadState);		if(!Callback(returnValue)) {			PyThreadState_Swap(oldThreadState);			return;		}	}}

	CAddContactDlg(ADDCONTACTSTRUCT *acs) :		CDlgBase(g_hInst, IDD_ADDCONTACT),		m_chkAdded(this, IDC_ADDED),		m_chkAuth(this, IDC_AUTH),		m_chkOpen(this, IDC_OPEN_WINDOW),		m_btnOk(this, IDOK),		m_group(this, IDC_GROUP),		m_authReq(this, IDC_AUTHREQ),		m_myHandle(this, IDC_MYHANDLE)	{		m_chkAuth.OnChange = Callback(this, &CAddContactDlg::OnAuthClicked);		m_chkOpen.OnChange = Callback(this, &CAddContactDlg::OnOpenClicked);		m_btnOk.OnClick = Callback(this, &CAddContactDlg::OnOk);		m_acs = *acs;	}

bool cConnection::Read(void){	char	temp[8193];	int		size;	size = Socket->recv(temp, sizeof(temp)-1);	if (size >= 0)	{		Buffer.Add(temp, size);		temp[size] = 0;	}	if (Buffer.Get() && strstr(Buffer.Get(), "/r/n/r/n"))	{	// found the blank line		temp[0] = 0;		Buffer.Add(temp, 1);		Reading = false;		Buffer.FreeBeforeNextAdd();		if (Callback)		{			Callback(this);		}		return ReadCallback();	}	return false;}

void cvar_t::ForceSet (const char *val){	if (m_Flags & CVAR_LATCH &&		 !(m_Flags & CVAR_SERVERINFO && baseapp != server) &&		 !(m_Flags & CVAR_CLIENTINFO && baseapp != client))	{		m_Flags |= CVAR_MODIFIED;		if(val)			m_LatchedString = val;		else			m_LatchedString = "";	}	else	{		m_Flags |= CVAR_MODIFIED;		if(val)			m_String = val;		else			m_String = "";		m_Value = atof (val);		if (m_Flags & CVAR_USERINFO)			D_UserInfoChanged (this);		if (m_Flags & CVAR_SERVERINFO)			D_SendServerInfoChange (this, val);		if (m_UseCallback)			Callback ();	}	m_Flags &= ~CVAR_ISDEFAULT;}

 static Callback from_function_e(UserData userdata) {     return Callback(         [=](Args && ... args) -> R {             return function_caller_e<UserData, Function>(std::forward<Args>(args)..., userdata);         }     ); }

SoundHandle::~SoundHandle(){    if(hasCallback == true)    {        Callback();    }    /*     * i was running into a bug because i didnt do the isvalid / NULL     * checks ..     * sources get removed even if you dont do RemoveSource     * but it will not dereference them! ..     */    if(sndstream != NULL)    {        SoundSystemManager::GetSingleton().GetSoundSystem()->RemoveStream(sndstream);    }    if(sndsource != NULL)    {        SoundSystemManager::GetSingleton().GetSoundSystem()->RemoveSource(sndsource);    }    if(delayActive)    {        SoundSystemManager::GetSingleton().eventTimer->RemoveTimerEvent(this);    }}

CJabberDlgGcJoin::CJabberDlgGcJoin(CJabberProto *proto, TCHAR *jid) :	CSuper(proto, IDD_GROUPCHAT_JOIN, NULL),	btnOk(this, IDOK),	m_jid(mir_tstrdup(jid)){	btnOk.OnClick = Callback(this, &CJabberDlgGcJoin::OnBtnOk);}

uint8_t Endpoint_Read_Stream_BE(void* Buffer, uint16_t Length#if !defined(NO_STREAM_CALLBACKS)                                 , uint8_t (* const Callback)(void)#endif								 ){	uint8_t* DataStream = (uint8_t*)(Buffer + Length - 1);	uint8_t  ErrorCode;		if ((ErrorCode = Endpoint_WaitUntilReady()))	  return ErrorCode;	while (Length--)	{		if (!(Endpoint_ReadWriteAllowed()))		{			Endpoint_ClearCurrentBank();			#if !defined(NO_STREAM_CALLBACKS)			if ((Callback != NULL) && (Callback() == STREAMCALLBACK_Abort))			  return ENDPOINT_RWSTREAM_ERROR_CallbackAborted;			#endif			if ((ErrorCode = Endpoint_WaitUntilReady()))			  return ErrorCode;		}				*(DataStream--) = Endpoint_Read_Byte();	}		return ENDPOINT_RWSTREAM_ERROR_NoError;}

/** The constructor  *  *  Create a new MessageBox with an empty message.  *  * /param vTitle The title of the message box  * /param vGui   The GUI object  * /param sid    The skin identifier  *  */RainbruRPG::OgreGui::RbMessageBox::RbMessageBox( const String& vTitle, GUI* vGui, OgreGuiSkinID sid):  Dialog(Vector4(10, 10, 300, 100), vTitle, vGui, sid),  message(""),  title(vTitle),  width(300),  height(100),  caption(NULL),  btnOk(NULL){  // Center the dialog  unsigned int rwWidth, rwHeight, posX, posY;  rwWidth=GameEngine::getSingleton().getRenderWindow()->getWidth();  rwHeight=GameEngine::getSingleton().getRenderWindow()->getHeight();  posX=(rwWidth/2)-(width/2);  posY=(rwHeight/2)-(height/2);  LOGI(_("Centering the Dialog"));  move(posY, posY);  // Adds default widgets  Vector4 labDim=Vector4(2, 24, width-20, 30);  caption=new Label( labDim, "Unset", this );  addWidget(caption);    Vector4 btnDim=Vector4( (width/2)-50, height-30, 100, 24 );  btnOk=new PushButton (btnDim, "OK", Callback(this), this);  addWidget(btnOk);}

 static Callback from_method_e(C * instance, UserData userdata) {     return Callback(         [=](Args && ... args) -> R {             return method_caller_e<C, UserData, CMethod>(instance, std::forward<Args>(args)..., userdata);         }     ); }

uint8_t Pipe_Write_Stream_LE(const void* Data, uint16_t Length#if !defined(NO_STREAM_CALLBACKS)                                 , uint8_t (* const Callback)(void)#endif								 ){	uint8_t* DataStream = (uint8_t*)Data;	uint8_t  ErrorCode;		if ((ErrorCode = Pipe_WaitUntilReady()))	  return ErrorCode;	while (Length--)	{		if (!(Pipe_ReadWriteAllowed()))		{			Pipe_ClearCurrentBank();							#if !defined(NO_STREAM_CALLBACKS)			if ((Callback != NULL) && (Callback() == STREAMCALLBACK_Abort))			  return PIPE_RWSTREAM_ERROR_CallbackAborted;			#endif			if ((ErrorCode = Pipe_WaitUntilReady()))			  return ErrorCode;		}		Pipe_Write_Byte(*(DataStream++));	}	return PIPE_RWSTREAM_ERROR_NoError;}

 static Callback from_method(C * instance) {     return Callback(         [=](Args && ... args) -> R {             return method_caller<C, CMethod>(instance, std::forward<Args>(args)...);         }     ); }

    Widget& Widget::operator= (const Widget& right)    {        // Make sure it is not the same widget        if (this != &right)        {            this->sf::Drawable::operator=(right);            this->Transformable::operator=(right);            this->CallbackManager::operator=(right);            m_Enabled             = right.m_Enabled;            m_Visible             = right.m_Visible;            m_Loaded              = right.m_Loaded;            m_WidgetPhase         = right.m_WidgetPhase;            m_Parent              = right.m_Parent;            m_Opacity             = right.m_Opacity;            m_MouseHover          = false;            m_MouseDown           = false;            m_Focused             = false;            m_AllowFocus          = right.m_AllowFocus;            m_AnimatedWidget      = right.m_AnimatedWidget;            m_DraggableWidget     = right.m_DraggableWidget;            m_ContainerWidget     = right.m_ContainerWidget;            m_Callback            = Callback();            m_Callback.widget     = nullptr;            m_Callback.widgetType = right.m_Callback.widgetType;            m_Callback.id         = right.m_Callback.id;        }        return *this;    }