list数组转tree树结构，并排序

setTree(data) {
  const tree = [];
  data.forEach(item => {
     const children = this.list.filter(e => e.parentId === item.id)
     if(children.length) {
        item.children = children
        this.setTree(item.children)
     }
     if(!item.parentId){
        tree.push(item)
     }
  })    
   tree.sort((a, b) => {a.order - b.order})
   return tree;
  
}