充电五分钟...

let list =[ {id:1, name:'A', parentId:0}, {id:2, name:'B', parentId:0}, {id:3, name:'C', parentId:1}, {id:4, name:'D', parentId:1}, {id:5, name:'E', parentId:2}, {id:6, name:'F', parentId:3}, {id:7, name:'G', parentId:2}, {i