今天碰到一个需求，要在动作结束的回调函数中取到当前动作的精灵，实现在执行动作之后自动 remove 掉这个精灵。查了一下，没有结果。然后看了一下 API ，发现利用 cc.CallFunc 构造函数中的 data 参数可以解决这个问题。
下面是 cc.CallFunc 的构造函数和 init 方法的实现：
ctor:function(selector, selectorTarget, data){
cc.FiniteTimeAction.prototype.ctor.call(this);
if(selector !== undefined){
if(selectorTarget === undefined)
this.initWithFunction(selector);
else this.initWithFunction(selector, selectorTarget, data);
}
},
initWithFunction:function (selector, selectorTarget, data) {
if (selectorTarget) {
this._data = data;
this._callFunc = selector;
this._selectorTarget = selectorTarget;
}
else if (selector)
this._function = selector;
return true;
},
参数 selector 和 selectorTarget 不赘述。注意到在 init 方法中，将 ctor 方法传入的 data 赋给了 this 的 _data 。
再看它的 execute 方法 ：
execute:function () {
if (this._callFunc != null) //CallFunc, N, ND
this._callFunc.call(this._selectorTarget, this.target, this._data);
else if(this._function)
this._function.call(null, this.target);
},
在执行这个回调的时候将 this._data 传入了原方法中，这样我们就可以将当前动作精灵指针传入回调函数，并在回调中取得它。
先构造一个动作队列并运行，代码如下：
var actionSprite = new cc.Sprite("res/me.png");
actionSprite.setAnchorPoint(0, 0);
actionSprite.x = 0;
actionSprite.y = 0;
this.addChild(actionSprite, 1);
var moveAction0 = cc.MoveBy(0.5, cc.p(cc.winSize.width/2, 0));
var moveAction1 = cc.MoveBy(0.5, cc.p(0, cc.winSize.height/2));
var moveAction2 = cc.MoveBy(0.5, cc.p(-cc.winSize.width/2, 0));
var moveAction3 = cc.MoveBy(0.5, cc.p(0, -cc.winSize.height/2));
var actionCallbackFunction = cc.CallFunc(this.actionCallbackFunction, this);
var actionFinishCallbackFunction = cc.CallFunc(this.actionFinishCallFunction, this);
var actionArray = [];
actionArray.push(moveAction0);
actionArray.push(actionCallbackFunction);
actionArray.push(moveAction1);
actionArray.push(actionCallbackFunction);
actionArray.push(moveAction2);
actionArray.push(actionCallbackFunction);
actionArray.push(moveAction3);
actionArray.push(actionFinishCallbackFunction);
var actionSequence = cc.Sequence(actionArray);
actionSprite.runAction(actionSequence);
},
actionCallbackFunction : function(){
cc.log("Action Callback Function");
},
actionFinishCallFunction : function(){
cc.log("Action Finish Callback Function");
},
下面对以上代码做一下小修改，来取得执行动作的精灵。
首先我们在构造回调函数时要将精灵的指针作为 data 参数传入：
var actionCallbackFunction = cc.CallFunc(this.actionCallbackFunction, this, actionSprite);
var actionFinishCallbackFunction = cc.CallFunc(this.actionFinishCallFunction, this, actionSprite);
其次我们要在定义回调方法的参数表中加入 data ，以便在函数实现中使用它：
actionCallbackFunction : function(data){
cc.log("Action Callback Function");
if (data != null && data != "undefine"){
cc.log("Get Data");
cc.log(typeof data);
cc.log(data.x);
cc.log(data.y);
}
},
actionFinishCallFunction : function(data){
cc.log("Action Finish Callback Function");
if (data != null && data != "undefine"){
cc.log("Get Data");
cc.log(typeof data);
cc.log(data.x);
cc.log(data.y);
}
data.removeFromParent();
},
运行试试看～
控制台这一部分输出为：
JS: Action Callback Function
JS: Get Data
JS: object
JS: 400
JS: 0
JS: Action Callback Function
JS: Get Data
JS: object
JS: 400
JS: 225
JS: Action Callback Function
JS: Get Data
JS: object
JS: 0
JS: 225
JS: Action Finish Callback Function
JS: Get Data
JS: object
JS: 0
JS: 0
看到在每一次动作执行完毕后输出 data 类型为 object 和精灵当前的坐标，最后的 removeFromParent() 也成功了。
接下来试一下来构造一个函数，返回一个动作队列。这样，只要创建动作队列然后在精灵上 runAction 就自动实现了精灵动作并在动作结束之后自动清掉这个精灵。
创建动作队列的代码如下：
createActionSequence : function(actionSpritePointer){
var moveAction0 = cc.MoveBy(0.5, cc.p(cc.winSize.width/2, 0));
var moveAction1 = cc.MoveBy(0.5, cc.p(0, cc.winSize.height/2));
var moveAction2 = cc.MoveBy(0.5, cc.p(-cc.winSize.width/2, 0));
var moveAction3 = cc.MoveBy(0.5, cc.p(0, -cc.winSize.height/2));
var actionCallbackFunction = cc.CallFunc(this.actionCallbackFunction, this, actionSpritePointer);
var actionFinishCallbackFunction = cc.CallFunc(this.actionFinishCallFunction, this, actionSpritePointer);
var actionArray = [];
actionArray.push(moveAction0);
actionArray.push(actionCallbackFunction);
actionArray.push(moveAction1);
actionArray.push(actionCallbackFunction);
actionArray.push(moveAction2);
actionArray.push(actionCallbackFunction);
actionArray.push(moveAction3);
actionArray.push(actionFinishCallbackFunction);
var actionSequence = cc.Sequence(actionArray);
return actionSequence;
}
参数 actionSpritePointer 要在创建时传入要执行这个动作队列的精灵，这样，就能把这个精灵的指针传入回调函数中。
创建动作队列并执行的代码如下：
var actionSprite0 = new cc.Sprite("res/me.png");
var actionSprite1 = new cc.Sprite("res/me.png");
actionSprite0.setAnchorPoint(0, 0);
actionSprite1.setAnchorPoint(1, 0);
actionSprite0.x = 0;
actionSprite0.y = 0;
actionSprite1.x = cc.winSize.width/2;
actionSprite1.y = 0;
this.addChild(actionSprite0);
this.addChild(actionSprite1);
var actionSequence0 = this.createActionSequence(actionSprite0);
var actionSequence1 = this.createActionSequence(actionSprite1);
cc.log(typeof actionSequence0);
actionSprite0.runAction(actionSequence0);
actionSprite1.runAction(actionSequence1);
谢谢观赏，如果有错误，欢迎指正～
