egret引擎生命周期相关

1.游戏开发生命周期

关于游戏开发中的生命周期相关的知识，参考一下：https://www.jianshu.com/p/ebc9e087676e

2.egret 2d引擎中的生命周期

对于egret 2D中的生命周期我们来了解一下：
(1)心跳
egret的 SystemTicker，是引擎的心跳计时器，egret通过SystemTicker来执行每一帧的eventLoop，渲染等操作。
保持游戏框架的运行。
pause():void 是暂停心跳的操作。
resume():void 是恢复心跳
update函数，egret在运行每帧是回调。
(2)计时器
egret.startTick(callBack: (timeStamp: number) => boolean, thisObject: any):void;
egret开启计时器的注册函数。
egret.stopTick(callBack: (timeStamp: number) => boolean, thisObject: any): void;
egret停止计时器函数。
在游戏中经常会出现有些对象随着时间的变化而变化的。一旦有这种需求，那么就需要用到计时器来记录时间并且在合适的时间
里对物品的属性变化进行操作。
如果有大量的这类型的需求，那么我们应该集中来管理，那么就需要一个计时器回调函数管理器。
心跳管理器

/*** Timer管理器*/
class TimerMgr extends BaseClass {private _handlers: Array<TimerHandler>;private _currTime: number;private _currFrame: number;private currHandler: TimerHandler = null;private nexthandles: Array<TimerHandler>;/*** 构造函数*/public constructor() {super();this._handlers = [];this.nexthandles = null;this._currTime = egret.getTimer();this._currFrame = 0;egret.startTick(this.onEnterFrame, this);}public static ins(): TimerMgr {return super.ins() as TimerMgr;}public getFrameId(): number {return this._currFrame;}public getCurrTime(): number {return this._currTime;}// 从大到小排序public static binFunc(b1: TimerHandler, b2: TimerHandler): number {if (b1.exeTime > b2.exeTime) return -1;else if (b1.exeTime < b2.exeTime) return 1;else return 0;}private static DeleteHandle(handler: TimerHandler) {handler.clear();ObjPool.push(handler);}/*** 每帧执行函数* @param frameTime*/private onEnterFrame(time: number): boolean {this._currFrame++;this._currTime = egret.getTimer();let currTime: number = 0;// process the nextlist firstlet nexthandles = this.nexthandles;this.nexthandles = null;if (nexthandles && nexthandles.length > 0) {for (let handler of nexthandles) {handler.method.call(handler.methodObj);TimerMgr.DeleteHandle(handler);}nexthandles = null;}if (this._handlers.length <= 0) return false;let handler = this._handlers[this._handlers.length - 1];while (handler.exeTime <= this._currTime) {this.currHandler = handler = this._handlers.pop();let times = (this._currTime - handler.exeTime) / handler.delay;if (times > 1) {handler.method.call(handler.methodObj, times);} else {handler.method.call(handler.methodObj);}currTime = egret.getTimer();handler.exeTime = currTime + handler.delay;let repeat: boolean = handler.forever;if (!repeat) {if (handler.repeatCount > 1) {handler.repeatCount--;repeat = true;} else {if (handler.onFinish) {handler.onFinish.apply(handler.finishObj);}}}if (repeat) {let index = Algorithm.binSearch(this._handlers, handler, TimerMgr.binFunc);this._handlers.splice(index, 0, handler);}else {TimerMgr.DeleteHandle(handler);}if (currTime - this._currTime > 5) break;if (this._handlers.length <= 0) break;else handler = this._handlers[this._handlers.length - 1];}this.currHandler = null;return false;}private create(startTime: number, delay: number, repeat: number, method: Function, methodObj: any,onFinish: Function, fobj: any, remove: boolean = false): void {if (delay < 0 || repeat < 0 || method == null) {return;}let handler: TimerHandler = ObjPool.pop("TimerHandler");handler.forever = repeat == 0;handler.repeatCount = repeat;handler.delay = delay;handler.method = method;handler.methodObj = methodObj;handler.onFinish = onFinish;handler.finishObj = fobj;handler.exeTime = startTime + this._currTime;// this._handlers.push(handler);let index = Algorithm.binSearch(this._handlers, handler, TimerMgr.binFunc);this._handlers.splice(index, 0, handler);}/**** 定时执行* @param delay 执行间隔:毫秒* @param repeat 执行次数, 0为无限次* @param method 执行函数* @param methodObj 执行函数所属对象* @param onFinish 完成执行函数* @param fobj 完成执行函数所属对象* @param remove 是否删除已经存在的**/public doTimer(delay: number, repeat: number, method: Function, methodObj: any, onFinish: Function = null, fobj: any = null, remove: boolean = false): void {this.create(delay, delay, repeat, method, methodObj, onFinish, fobj, remove);}/**** 定时执行* @param startTime 延迟多久第一次执行* @param delay 执行间隔:毫秒* @param repeat 执行次数, 0为无限次* @param method 执行函数* @param methodObj 执行函数所属对象* @param onFinish 完成执行函数* @param fobj 完成执行函数所属对象* @param remove 是否删除已经存在的**/public doTimerDelay(startTime: number, delay: number, repeat: number, method: Function, methodObj: any, onFinish: Function = null, fobj: any = null): void {this.create(startTime, delay, repeat, method, methodObj, onFinish, fobj);}/** 下一帧执行，且只执行一次*/public doNext(method: Function, methodObj: any) {let handler: TimerHandler = ObjPool.pop("TimerHandler");handler.method = method;handler.methodObj = methodObj;if (!this.nexthandles)this.nexthandles = [];this.nexthandles.push(handler);}/*** 清理* @param method 要移除的函数* @param methodObj 要移除的函数对应的对象*/public remove(method: Function, methodObj: any): void {let currHandler = this.currHandler;if (currHandler && currHandler.method == method &&currHandler.methodObj == methodObj) {currHandler.forever = false;currHandler.repeatCount = 0;}for (let i = this._handlers.length - 1; i >= 0; i--) {let handler = this._handlers[i];if (handler.method == method && handler.methodObj == methodObj) {this._handlers.splice(i, 1);TimerMgr.DeleteHandle(handler);}}}/*** 清理* @param methodObj 要移除的函数对应的对象*/public removeAll(methodObj: any): void {let currHandler = this.currHandler;if (currHandler && currHandler.methodObj == methodObj) {currHandler.forever = false;currHandler.repeatCount = 0;}for (let i = this._handlers.length - 1; i >= 0; i--) {let handler = this._handlers[i];if (handler.methodObj == methodObj) {this._handlers.splice(i, 1);TimerMgr.DeleteHandle(handler);}}}/*** 检测是否已经存在* @param method* @param methodObj**/public isExists(method: Function, methodObj: any): boolean {for (let handler of this._handlers) {if (handler.method == method && handler.methodObj == methodObj) {return true;}}return false;}
}class TimerHandler {/**执行间隔*/public delay: number = 0;/**是否重复执行*/public forever: boolean = false;/**重复执行次数*/public repeatCount: number = 0;/**执行时间*/public exeTime: number = 0;/**处理函数*/public method: Function;/**处理函数所属对象*/public methodObj: any;/**完成处理函数*/public onFinish: Function;/**完成处理函数所属对象*/public finishObj: any;/**清理*/public clear(): void {this.method = null;this.methodObj = null;this.onFinish = null;this.finishObj = null;this.forever = false;}
}

(3)帧事件
帧事件是egret 每一帧都发出的一个基础事件类型。
帧事件的是生命周期的体现，相当于unity的updata函数。
帧事件的监听，继承自DisplayObject

this.addEventListener(egret.Event.ENTER_FRAME，this.onUpdata，this);

移除

this.removeEventListener(egret.Event.ENTER_FRAME，this.onUpdata，this);