vue子传父关于.sync与$emit的实现

<folder-tree
 :folder-list.sync="folderList"
 :file-list.sync="fileList"
 :folder-drop="folderDrop"
 :file-drop="fileDrop"
 :beforDelete="beforeDelete"
/>
import FolderTree from '_c/folder-tree'
export default {
 ponents: {
  FolderTree
 },
 }

<Tree :data="folderTree" :render="renderFunc"></Tree>

 let updateListName = isFolder ? 'folderList' : 'fileList'
 this.$emit(`update:${updateListName}`, list)

// this.$emit('update:folder-tree',100); //无效
this.$emit('update:folderTree',100); //有效
//......
<folder-tree v-bind:folder-tree.sync="test"></folder-tree>

this.$emit('update:folder-tree',100); //有效
//this.$emit('update:folderTree',100); // 无效
 
 //......
 <folderTree v-bind:father-num="test" v-on:update:folder-tree="test=$event" ></folderTree>