场景跳转时获取场景资源加载进度

    直接撸代码：

FastBattle是场景的名字，直接配合progressBar（进度条）使用即可

        ①   获取loadScene的加载进度时：

cc.loader.onProgress = function (completedCount, totalCount, item) {
    var progress = (completedCount / totalCount).toFixed(2);
    console.log('加载进度');
    cc.log("completedCount = "+completedCount+",totalCount="+totalCount+",progress="+progress);
    if(item && item.uuid && progress > self.loadBar.progress){
        self.loadBar.progress = progress;
    }
};
cc.director.loadScene('FastBattle',null,function () {
    cc.loader.onProgress = null;
});

其中loadBar是一个ProgressBar组件

      ②获取preloadScene的加载进度时：

cc.director.preloadScene('FastBattle',(completedCount, totalCount, item) => {
    cc.log('加载进度显示');
    cc.log("completedCount = "+completedCount+",totalCount="+totalCount);
    cc.log('百分比：'+Math.floor(completedCount / totalCount*100));
},(error) => {
    console.log(error);
});