message: fix(DropdownMenu): menu ref may not exist in some cases
diff: @@ -53,8 +53,11 @@ export default createComponent({
  methods: {
  updateOffset() {
  - const { menu } = this.$refs;
  - const rect = menu.getBoundingClientRect();
  + if (!this.$refs.menu) {
  + return;
  + }
  +
  + const rect = this.$refs.menu.getBoundingClientRect();
  if (this.direction === 'down') {
  this.offset = rect.bottom;
  