Element-ui中Tree的使用，以及全选反选获取id

<el-checkbox v-model="checkAll" @change="handleCheckAllChange">全选</el-checkbox>
                <el-tree
                    :data="data"
                    show-checkbox
                    default-expand-all
                    node-key="module_id"
                    ref="tree"
                    highlight-current
                    :props="defaultProps"
                    @check="nodeClick"
                ></el-tree>

data() {
        return {
            checkAll: false,
            select_box: [],
            data: [], //tree
            defaultProps: {
                children: ‘child‘,
                label: ‘module_name‘
            }
        };
    },

 handleCheckAllChange(val) {
            if (this.checkAll) {
//全选
                this.$nextTick(function () {
                    this.$refs.tree.setCheckedNodes(this.data);
                });
            } else {
//反选
                this.$nextTick(function () {
                    this.$refs.tree.setCheckedKeys([]);
                });
            }
            this.$nextTick(function () {
//获取id
                let select_box = [];
                this.$refs.tree.getCheckedNodes().forEach((item) => {
                    select_box.push(item.module_id);
                });
                this.select_box = select_box;
                // console.log(this.select_box, ‘select_box888‘);
            });
        },
        nodeClick(data, node, e) {
//点击的时候获取到所有选中的
            // console.log(this.$refs.tree.getCheckedNodes(), ‘console.log(this.$refs.tree.getCheckedNodes());‘);
            let select_box = [];
            this.$refs.tree.getCheckedNodes().forEach((item) => {
                select_box.push(item.module_id);
            });
            this.select_box = select_box;
            console.log(this.select_box, ‘select_box‘);
        },