请问怎么系统图片要预加载，其他图片不需要?

ccwkgg

请问怎么系统图片要预加载，其他图片不需要?
Scene_Boot.loadSystemImages = function() {//预加载图片
    ImageManager.reserveSystem('IconSet');
    ImageManager.reserveSystem('Balloon');
    ImageManager.reserveSystem('Shadow1');
    ImageManager.reserveSystem('Shadow2');
    ImageManager.reserveSystem('Damage');
    ImageManager.reserveSystem('States');
    ImageManager.reserveSystem('Weapons1');
    ImageManager.reserveSystem('Weapons2');
    ImageManager.reserveSystem('Weapons3');
    ImageManager.reserveSystem('ButtonSet');
};
用自定义图片，还得先预加载一遍