1.什么是断言?
断言assert 是仅在Debug 版本起作用的宏,它用于检查“不应该”发生的情况。如果是Release版本,编译器忽略所有的断言(看成空语句)。
CC_ASSERT(条件)
#define CC_ASSERT(cond) assert(cond)
CCAsert(条件,"打印信息")
#if COCOS2D_DEBUG > 0extern bool CC_DLL cc_assert_script_compatible(const char *msg);#define CCAssert(cond, msg) do { \ if (!(cond)) { \ if (!cc_assert_script_compatible(msg) && strlen(msg)) \ cocos2d::CCLog("Assert failed: %s", msg); \ CC_ASSERT(cond); \ } \ } while (0)#else#define CCAssert(cond, msg) ((void)(cond))#endif
例子:
//addChild方法,如果要添加的子节点为空,就停住了,并打印信息“Argument must be non-nil”void CCNode::addChild(CCNode *child){ //不为空不成立,就是为空啦 CCAssert( child != NULL, "Argument must be non-nil"); this->addChild(child, child->m_nZOrder, child->m_nTag);}
2.函数回调,主要有三种方式(无参数,一个参数,二个参数)
void call1();void call2(CCNode* node);void call3(CCNode* node,void* data);
实现:
void HelloWorld::call1(){ CCLog("call1"); }void HelloWorld::call2(CCNode* node){ CCLog("call2");}void HelloWorld::call3(CCNode* node,void* data){ CCLog("call3"); CCSprite* sp =(CCSprite*) data; sp->setScale(2.0f); }
函数回调:
CCSprite* sp = CCSprite::create("CloseNormal.png"); sp->setPosition(CCPointZero); addChild(sp); CCJumpTo* jump = CCJumpTo::create(1, ccp(400,20), 60, 8);// 无参 CCCallFunc* fun1 = CCCallFunc::create(this, callfunc_selector(HelloWorld::call1));//一个参数 CCCallFunc* fun2 = CCCallFuncN::create(this, callfuncN_selector(HelloWorld::call2));//两个参数 CCCallFunc* fun3 = CCCallFuncND::create(this, callfuncND_selector(HelloWorld::call3),(void*)sp); CCSequence* seq = CCSequence::create(jump,fun1,fun2,fun3,0); sp->runAction(seq);
3.CCProgressTo使用:
//TestCpp中的例子 CCSprite* sp = CCSprite::create("CloseNormal.png"); sp->setPosition(CCPointZero); addChild(sp); CCSize s = CCDirector::sharedDirector()->getWinSize(); CCProgressTo *to1 = CCProgressTo::create(2, 100); CCProgressTimer *left = CCProgressTimer::create(sp); left->setType( kCCProgressTimerTypeRadial );//圆形进度 addChild(left); left->setPosition(ccp(100, s.height/2)); left->runAction( CCRepeatForever::create(to1));
哈哈,一天一点进步,加油