我这边游戏需要在对象碰撞的时候，判断碰撞的冲量，根据冲量来判断是否摧毁物品。但官方封装的方法，直接把PostSolve给忽略了。。
无奈只能自己加一份，为了尽量不修改引擎源码，导致不兼容的问题，我使用了prototype覆盖的方法。额外增加了一个类。对于原来的laya.physics.js类，只需要添加把ContactListener这个类导出的方法即可。
具体参见我这个类。
使用的时候，只需要在外部调用初始化方法就行了。
[code]
const BoxExtraFunctions = {}
// 在laya.physics.js里添加这些方法，将ContactListener这个类导出来。
// Laya.ClassUtils.regClass("laya.physics.ContactListener", ContactListener);
// Laya.ClassUtils.regClass("Laya.ContactListener", ContactListener);
// exports.ContactListener = ContactListener;


BoxExtraFunctions.addExtra = function(){
    //注册预碰撞功能。
    Laya.ContactListener.prototype.PostSolve = function(contact, impulse) {
        Laya.Physics.I._eventList.push(impulse, contact);
    }

    Laya.Event.TRIGGER_POST_SOLVE = "trigger_post_solve"

    Laya.Physics.prototype._sendEvent = function(type, contact) {
        var colliderA = contact.GetFixtureA().collider;
        var colliderB = contact.GetFixtureB().collider;
        var ownerA = colliderA.owner;
        var ownerB = colliderB.owner;
        contact.getHitInfo = function () {
            var manifold = new this.box2d.b2WorldManifold();
            this.GetWorldManifold(manifold);
            var p = manifold.points[0];
            p.x *= Physics.PIXEL_RATIO;
            p.y *= Physics.PIXEL_RATIO;
            return manifold;
        };
        if (ownerA) {
            var args = [colliderB, colliderA, contact];
            if (type === 0) {
                ownerA.event(Laya.Event.TRIGGER_ENTER, args);
                if (!ownerA["_triggered"]) {
                    ownerA["_triggered"] = true;
                }
                else {
                    ownerA.event(Laya.Event.TRIGGER_STAY, args);
                }
            }
            else if(type === 1){
                ownerA["_triggered"] = false;
                ownerA.event(Laya.Event.TRIGGER_EXIT, args);
            }
            else{
                ownerA.event(Laya.Event.TRIGGER_POST_SOLVE, args.concat(type));
            }
        }
        if (ownerB) {
            args = [colliderA, colliderB, contact];
            if (type === 0) {
                ownerB.event(Laya.Event.TRIGGER_ENTER, args);
                if (!ownerB["_triggered"]) {
                    ownerB["_triggered"] = true;
                }
                else {
                    ownerB.event(Laya.Event.TRIGGER_STAY, args);
                }
            }
            else if(type === 1){
                ownerB["_triggered"] = false;
                ownerB.event(Laya.Event.TRIGGER_EXIT, args);
            }
            else{
                ownerB.event(Laya.Event.TRIGGER_POST_SOLVE, args.concat(type));
            }
        }
    }

    Laya.Script.prototype.onTriggerPostSolve = function(other, self, contact, impulse) {
        
    }

    Laya.Script.prototype._onEnable = function(){
            let proto = Laya.Script.prototype
            if (this.onTriggerEnter !== proto.onTriggerEnter) {
                this.owner.on(Laya.Event.TRIGGER_ENTER, this, this.onTriggerEnter);
            }
            if (this.onTriggerStay !== proto.onTriggerStay) {
                this.owner.on(Laya.Event.TRIGGER_STAY, this, this.onTriggerStay);
            }
            if (this.onTriggerExit !== proto.onTriggerExit) {
                this.owner.on(Laya.Event.TRIGGER_EXIT, this, this.onTriggerExit);
            }
            if (this.onTriggerPostSolve !== proto.onTriggerPostSolve) {
                this.owner.on(Laya.Event.TRIGGER_POST_SOLVE, this, this.onTriggerPostSolve);
            }
            if (this.onMouseDown !== proto.onMouseDown) {
                this.owner.on(Laya.Event.MOUSE_DOWN, this, this.onMouseDown);
            }
            if (this.onMouseUp !== proto.onMouseUp) {
                this.owner.on(Laya.Event.MOUSE_UP, this, this.onMouseUp);
            }
            if (this.onClick !== proto.onClick) {
                this.owner.on(Laya.Event.CLICK, this, this.onClick);
            }
            if (this.onStageMouseDown !== proto.onStageMouseDown) {
                ILaya.stage.on(Laya.Event.MOUSE_DOWN, this, this.onStageMouseDown);
            }
            if (this.onStageMouseUp !== proto.onStageMouseUp) {
                ILaya.stage.on(Laya.Event.MOUSE_UP, this, this.onStageMouseUp);
            }
            if (this.onStageClick !== proto.onStageClick) {
                ILaya.stage.on(Laya.Event.CLICK, this, this.onStageClick);
            }
            if (this.onStageMouseMove !== proto.onStageMouseMove) {
                ILaya.stage.on(Laya.Event.MOUSE_MOVE, this, this.onStageMouseMove);
            }
            if (this.onDoubleClick !== proto.onDoubleClick) {
                this.owner.on(Laya.Event.DOUBLE_CLICK, this, this.onDoubleClick);
            }
            if (this.onRightClick !== proto.onRightClick) {
                this.owner.on(Laya.Event.RIGHT_CLICK, this, this.onRightClick);
            }
            if (this.onMouseMove !== proto.onMouseMove) {
                this.owner.on(Laya.Event.MOUSE_MOVE, this, this.onMouseMove);
            }
            if (this.onMouseOver !== proto.onMouseOver) {
                this.owner.on(Laya.Event.MOUSE_OVER, this, this.onMouseOver);
            }
            if (this.onMouseOut !== proto.onMouseOut) {
                this.owner.on(Laya.Event.MOUSE_OUT, this, this.onMouseOut);
            }
            if (this.onKeyDown !== proto.onKeyDown) {
                ILaya.stage.on(Laya.Event.KEY_DOWN, this, this.onKeyDown);
            }
            if (this.onKeyPress !== proto.onKeyPress) {
                ILaya.stage.on(Laya.Event.KEY_PRESS, this, this.onKeyPress);
            }
            if (this.onKeyUp !== proto.onKeyUp) {
                ILaya.stage.on(Laya.Event.KEY_UP, this, this.onKeyUp);
            }
            if (this.onUpdate !== proto.onUpdate) {
                ILaya.updateTimer.frameLoop(1, this, this.onUpdate);
            }
            if (this.onLateUpdate !== proto.onLateUpdate) {
                ILaya.lateTimer.frameLoop(1, this, this.onLateUpdate);
            }
            if (this.onPreRender !== proto.onPreRender) {
                ILaya.lateTimer.frameLoop(1, this, this.onPreRender);
            }
            this.onEnable();
    }
}

export default BoxExtraFunctions[/code]