时间间隔定时器分析
1、//存放时间间隔定时器的结构// Hash Element used for "selectors with interval"typedef struct _hashSelectorEntry{ccArray*timers; //注：一个Target(如CCNode)中可能会添加多个时间间隔不同的定时器，//因为属于同一个Target，只有一个tHashTimerEntry结构，//但是时间间隔不同，回调不同的函数，所以//需要存放在一个数组中，数组中的元素类型是CCTimer，后面分析CCObject*target; // hash key (retained)unsigned inttimerIndex;CCTimer*currentTimer;boolcurrentTimerSalvaged;boolpaused;UT_hash_handlehh;} tHashTimerEntry;注：在CCScheduler中，，有一个成员变量，用于存放这种结构的哈希表 // Used for "selectors with interval" struct _hashSelectorEntry *m_pHashForTimers;2、添加时间间隔定时器/** The scheduled method will be called every 'interval' seconds.If paused is YES, then it won't be called until it is resumed.If 'interval' is 0, it will be called every frame, but if so, it's recommended to use 'scheduleUpdateForTarget:' instead.If the selector is already scheduled, then only the interval parameter will be updated without re-scheduling it again.repeat let the action be repeated repeat + 1 times, use kCCRepeatForever to let the action run continuouslydelay is the amount of time the action will wait before it'll start@since v0.99.3, repeat and delay added in v1.1@js NA@lua NA*/void scheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget, float fInterval, unsigned int repeat, float delay, bool bPaused);–>>void CCScheduler::scheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget, float fInterval, unsigned int repeat, float delay, bool bPaused){CCAssert(pfnSelector, "Argument selector must be non-NULL");CCAssert(pTarget, "Argument target must be non-NULL");//同一个Target只会有一个tHashTimerEntry结构tHashTimerEntry *pElement = NULL;HASH_FIND_INT(m_pHashForTimers, &pTarget, pElement);//如果不存在，则新增加一个if (! pElement){pElement = (tHashTimerEntry *)calloc(sizeof(*pElement), 1);pElement->target = pTarget;if (pTarget){pTarget->retain(); //对对象执行一次retain操作}//添加到m_pHashForTimers哈希表中HASH_ADD_INT(m_pHashForTimers, target, pElement);// Is this the 1st element ? Then set the pause level to all the selectors of this targetpElement->paused = bPaused;}else{CCAssert(pElement->paused == bPaused, "");}//同一个Target，如果有多个不同的定时器，存放到一个数组中if (pElement->timers == NULL){pElement->timers = ccArrayNew(10);}else{//如果某个pfnSelector回调函数已经存在，则只修改定时器的时间间隔for (unsigned int i = 0; i < pElement->timers->num; ++i){CCTimer *timer = (CCTimer*)pElement->timers->arr[i];if (pfnSelector == timer->getSelector()){CCLOG("CCScheduler#scheduleSelector. Selector already scheduled. Updating interval from: %.4f to %.4f", timer->getInterval(), fInterval);timer->setInterval(fInterval);return;}}ccArrayEnsureExtraCapacity(pElement->timers, 1);}//如果pfnSelector回调函数第一次加入，则创建一个CCTimer，并初始化CCTimer *pTimer = new CCTimer();pTimer->initWithTarget(pTarget, pfnSelector, fInterval, repeat, delay);ccArrayAppendObject(pElement->timers, pTimer);pTimer->release();}3、移除时间间隔定时器/** Unschedule a selector for a given target.If you want to unschedule the "update", use unscheudleUpdateForTarget.@since v0.99.3@lua NA*/void unscheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget);–>>源码：void CCScheduler::unscheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget){// explicity handle nil arguments when removing an objectif (pTarget == 0 || pfnSelector == 0){return;}//CCAssert(pTarget);//CCAssert(pfnSelector);tHashTimerEntry *pElement = NULL;HASH_FIND_INT(m_pHashForTimers, &pTarget, pElement);if (pElement){for (unsigned int i = 0; i < pElement->timers->num; ++i){CCTimer *pTimer = (CCTimer*)(pElement->timers->arr[i]);//把存放pfnSelector的CCTimer移除if (pfnSelector == pTimer->getSelector()){if (pTimer == pElement->currentTimer && (! pElement->currentTimerSalvaged)){pElement->currentTimer->retain();pElement->currentTimerSalvaged = true;}ccArrayRemoveObjectAtIndex(pElement->timers, i, true);// update timerIndex in case we are in tick:, looping over the actionsif (pElement->timerIndex >= i){pElement->timerIndex–;}//如果CCTimer数量为0，则移除tHashTimerEntry结构if (pElement->timers->num == 0){if (m_pCurrentTarget == pElement){m_bCurrentTargetSalvaged = true;}else{removeHashElement(pElement);}}return;}}}}–>>void CCScheduler::removeHashElement(_hashSelectorEntry *pElement){cocos2d::CCObject *target = pElement->target;ccArrayFree(pElement->timers);HASH_DEL(m_pHashForTimers, pElement);free(pElement);// make sure the target is released after we have removed the hash element// otherwise we access invalid memory when the release call deletes the target// and the target calls removeAllSelectors() during its destructortarget->release(); //对target对象执行一次release}
问候不一定要慎重其事，但一定要真诚感人
