idea展开所有文件夹、折叠所有文件夹 https://blog.csdn.net/kenzo2017/article/details/87689221?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-9.nonecase&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-9.nonecase