cocos2d 中的奧妙

首先不得不提，cocos2d 的文檔相當差，很多時候不得不直接看源代碼

 

• 事件響應：只有CCLayer才具有響應鍵盤鼠標事件的能力，除此之外還需：

self.isTouchEnabled = YES; ... //override -(void) registerWithTouchDispatcher { [[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:NO]; } //override - (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event { ... } 

注意如果不重寫registerWithTouchDispatcher方法，則他的默認實現是addStandardDelegate:而CCStandardTouchDelegate協議需要實現的方法有所不同：

@protocol CCTargetedTouchDelegate <NSObject> - (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event; @optional // touch updates: - (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event; - (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event; - (void)ccTouchCancelled:(UITouch *)touch withEvent:(UIEvent *)event; @end @protocol CCStandardTouchDelegate <NSObject> @optional - (void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event; - (void)ccTouchesMoved:(NSSet *)touches withEvent:(UIEvent *)event; - (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event; - (void)ccTouchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event; @end 

• 詭異的線：默認的CCTexture2D的rending模式爲Anti-Alias,這在多數情況下是我們需要的，但是在某些情況下，比如圖片重疊的時候，會產生詭異的類似陰影的線條。解決辦法是將CCSprite中的CCTexture2D的rending模式改爲Alias。這裏需要一點小技巧，因爲CCSprite的texture_實例變量不可讀寫，可以通過Category改變他：

 @interface CCSprite (Extend) - (void)setAliasTexParameters; @end @implementation CCSprite (Extend) - (void)setAliasTexParameters { [texture_ setAliasTexParameters]; } @end