mk_framework/mk_framework/assets/script/mk/system/LoaderSystem.ts

/**
 * @description 资源加载
 * @author xhx
 */
export default class LoaderSystem {
    private _bundle = null;
    public setBundle(bundle) {
        bundle && (this._bundle = bundle);
    }

    public getBundle() {
        return this._bundle || cc.resources;
    }
    /**
     * 
     * @param relative_path 资源路径
     * @param asset_type 资源类型
     * @param complete_callback 完成回调【选填】
     * @returns 对应的资源
     */
    public loadAssetByType<T extends typeof cc.Asset>(relative_path: string, asset_type: T, complete_callback?: Function): Promise<InstanceType<T>> {
        return new Promise((resolve: (data) => void, reject) => {
            this.getBundle().load(relative_path, asset_type, (error, asset) => {
                if (error) {
                    error('xx.loadAssetByType failed ... and path = ' + relative_path, '==error:', JSON.stringify(error));
                    reject();
                    return;
                } else {
                    complete_callback && complete_callback(asset);
                    resolve(asset);
                }
            });
        });
    }

    /**
     * 获取resource路径下资源地址数组
     * @param path 文件夹路径
     * @param type 文件类型
     * @returns [路径]
     */
    public getDirUrlsRecursion(path, type) {
        let urls = [];
        this.getBundle().getDirWithPath(path, type, urls);
        let arr_path = [];
        for (let i = 0; i < urls.length; i++) {
            const element = urls[i].path;
            arr_path.push(element);
        }
        return arr_path;
    }


    /**
     * 预加载资源 by 配置表 【暂未使用】
     * @param assets_config 配置表
     * @param progress_callback 进度回调
     * @param complete_callback 完成回调
     */
    public loadAssetsByConfig(assets_config, progress_callback, complete_callback) {
        let total_count = 0;
        let complete_count = 0;
        for (let i = 0; i < assets_config.length; i++) {
            let config = assets_config[i];
            let path = config.path;
            let type = config.type;

            let urls = [];
            this.getBundle().getDirWithPath(path, type, urls);
            total_count += urls.length;
            cc.log('预加载资源:%o', urls);
            let callback = config.cb;
            for (let i = 0; i < urls.length; i++) {
                let path = urls[i].path;
                this.getBundle().load(path, type, function (err, spriteFrame) {
                    if (err) {
                        cc.error(err.message || err);
                        return;
                    }
                    ++complete_count;
                    progress_callback && progress_callback(complete_count, total_count, spriteFrame);
                    callback && callback(spriteFrame);

                    if (complete_count === total_count) {
                        complete_callback && complete_callback();
                    }
                });
            }
        }
    }


    /**
     * 同步获取已经预加载的图集中的spriteframe 此接口进入游戏后生效
     * @param sprite_frame_name 要获取的纹理名字
     * @param path 图集路径
     * @returns cc.SpriteFrame
     */
    public getSpriteFrameFromAtlas(sprite_frame_name, path = '/Atlas'): cc.SpriteFrame {
        let urls = this.getDirUrlsRecursion(path, cc.SpriteAtlas);
        let len = urls.length;
        for (let i = 0; i < len; i++) {
            let url = urls[i];
            let atlas: any = this.getBundle().getRes(url, cc.SpriteAtlas);//resources.get
            if (atlas) {
                let sf = atlas.getSpriteFrame(sprite_frame_name);
                if (sf) return sf;
            }
        }
    }

    /**
     * 获取散图资源（需要在loading的时候首先加载）
     * @param sprite_frame_path 资源路径
     * @returns cc.SpriteFrame || null
     */
    public getSpriteFrame(sprite_frame_path: string): cc.SpriteFrame {
        let res = this.getBundle().getRes(sprite_frame_path, cc.SpriteFrame);
        return res;
    }

    /**
     * 获取图片纹理 by 图集 
     * @param sprite_frame_name 要获取的纹理名字
     * @param arr_atlas [图集列表]
     * @returns cc.SpriteFrame || null
     */
    public getSpriteFrameByArrAlst(sprite_frame_name: string, arr_atlas: Array<cc.SpriteAtlas>): cc.SpriteFrame {
        let count = arr_atlas.length;
        for (let i = 0; i < count; i++) {
            let _atlas = arr_atlas[i];
            let spf = _atlas.getSpriteFrame(sprite_frame_name);
            if (spf) return spf;
        }
        return null;
    }
};