CocosGameFrameWork/assets/Script/Game/MyApp/GameScene/Bullet.ts

import { _decorator, Animation, AnimationClip, BoxCollider2D, Collider2D, Component, Contact2DType, ICollisionEvent, IPhysics2DContact, Node, PhysicsSystem2D, SpriteFrame, UITransform } from 'cc';
import { Tools } from '../../Tools/Tools';
import { LifeBar } from './LifeBar';
const { ccclass, property } = _decorator;

@ccclass('Bullet')
export class Bullet extends Component {
    explodeframes: SpriteFrame[] = [];
    bulletFrames: SpriteFrame[] = [];
    explodeAni: Animation = null;
    bulletAni: Animation = null;

    //是否爆炸 true -> 爆炸
    isExplode: boolean = false;
    //子弹速度
    bulletSpeed: number = 100;
    //子弹方向
    direction: number = 1;
    //攻击力
    atk: number = null;
    //被攻击的节点
    targetNode: Node = null;
    //是否碰撞
    private _hasCollided: boolean = false;

    protected onLoad(): void {
        const collider = this.getComponent(Collider2D);
        if (collider) {
            //collider.on(Contact2DType.BEGIN_CONTACT, this._onBeginContact, this)
        }
    }
    start() {
        this.explodeAni = Tools.createAnimation(this.explodeframes, 5, this.node, AnimationClip.WrapMode.Normal);
        this.bulletAni = Tools.createAnimation(this.bulletFrames, 5, this.node, AnimationClip.WrapMode.Loop);
        //this.node.setPosition(0, 0, 0);
        this.setState(false);
    }

    setState(isExplode: boolean) {
        if (isExplode) {
            this.bulletSpeed = 0;
            this.explodeAni.play();
            this.explodeAni.once(Animation.EventType.FINISHED, () => {
                this.node.destroy()
            },
                this.node)
        } else {
            this.bulletAni.play();
        }
    }

    _onBeginContact(otherCollider: BoxCollider2D) {
        const lifeBar = this.targetNode.getComponent(LifeBar);
        lifeBar.updateProgressBar(lifeBar._curHp - this.atk);
        this.setState(true);
    }
    update(deltaTime: number) {
        this.move(deltaTime);
        this.onBulletCollision(this.targetNode);
    }

    move(dt: number) {
        let x = this.node.getWorldPosition().x;
        let y = this.node.getWorldPosition().y;
        let z = this.node.getWorldPosition().z;
        if (this.direction) {
            x = x + this.bulletSpeed * dt;
        } else {
            x = x - this.bulletSpeed * dt;
        }
        this.node.setWorldPosition(x, y, z)
    }

    // 处理子弹碰撞
    onBulletCollision(targetNode: Node) {
        if(this._hasCollided) return;
        if(!targetNode.isValid) return;
        const boxBullet = this.node.getComponent(UITransform).getBoundingBoxToWorld();
        const boxTarget = targetNode.getComponent(UITransform).getBoundingBoxToWorld();
        if (boxTarget.containsRect(boxBullet)) {
            const targetLifeBar = targetNode.getComponent(LifeBar);
            if((targetLifeBar._curHp - this.atk) <= 0){
                this.targetNode.destroy();
                this.node.destroy();
            }
            targetLifeBar.updateProgressBar(targetLifeBar._curHp - this.atk);
            this._hasCollided = true;
            this.setState(true);
        }
    }
    //targetNode为目标节点，子弹需要攻击的对象
    //如果子弹与targetNode碰撞，targetNode的hp(血量)将会减少子弹发射者的atk(攻击力);
    //同时子弹播放爆炸动画，播放结束后，子弹销毁
}