el-tree清空、设置默认值等功能

this.$refs.permissions.setCheckedKeys([]); //删除所有选中节点
this.$refs.permissions.setCheckedNodes([labvalojb]); //选中已选中节点

<el-tree
	ref="permissions"
	:default-checked-keys="permissionChecked"
	@check-change="handleCheckChangePermissions"  //节点选中状态发生变化时的回调
	@check="handleCheckChangeArea"  			//当复选框被点击的时候触发
	:data="PermissionsTreeData"
	show-checkbox
	node-key="id"
	:check-strictly="true"
	:props="PermissionTreeProps"   //子父节点定义
	>
</el-tree>

data(){
	return{
	 PermissionTreeProps: {
          children: "childrens",
          label: "name",
     },
}

一、编辑赋值时渲染tree
this.$ nextTick(() => {
this.$refs.permissions.setCheckedKeys([id]);
});

handleEdit(index, row) {
            this.button = 1;
            this.dialogFormVisible = true;
            this.form.id = row.id;
            this.form.name = row.name;
            this.form.action = row.action;
            this.form.name = row.name;
            this.form.description = row.description;
            this.form.http_method = this.radio;
            this.title = "修改权限";
            let id = row.pid;
            if (row.pid === 0) {
                id = row.id;
            }
            this.$nextTick(() => {
                this.$refs.permissions.setCheckedKeys([id]);
            });
        },

二、el-tree 实现单选

handleCheckChangeArea(data) {
    var labvalojb = data; //暂存选中节点
    this.$refs.permissions.setCheckedKeys([]); //删除所有选中节点
    this.$refs.permissions.setCheckedNodes([labvalojb]); //选中已选中节点
    this.form.pid = data.id;
},

三、节点选中状态发生变化时的回调

handleCheckChangePermissions() {
            this.form.permission_ids = this.$refs.permissions
                .getCheckedKeys()
                .toString();
        },