TDDropdownMenu _buildHeight(BuildContext context) {
  return TDDropdownMenu(
    direction: TDDropdownMenuDirection.up,
    onMenuOpened: (value) {
      print('打开第$value个菜单');
    },
    onMenuClosed: (value) {
      print('关闭第$value个菜单');
    },
    builder: (context) {
      return [
        TDDropdownItem(
          label: '最大高度限制',
          multiple: true,
          maxHeight: 200,
          options: [
            TDDropdownItemOption(label: '选项1', value: '1', selected: true),
            TDDropdownItemOption(label: '选项2', value: '2', selected: true),
            TDDropdownItemOption(label: '选项3', value: '3', selected: true),
            TDDropdownItemOption(label: '选项4', value: '4'),
            TDDropdownItemOption(label: '选项5', value: '5'),
            TDDropdownItemOption(label: '选项6', value: '6'),
            TDDropdownItemOption(label: '选项7', value: '7'),
            TDDropdownItemOption(label: '选项8', value: '8'),
            TDDropdownItemOption(label: '选项9', value: '9'),
            TDDropdownItemOption(label: '禁用选项', value: '10', disabled: true),
            TDDropdownItemOption(label: '禁用选项', value: '11', disabled: true),
            TDDropdownItemOption(label: '禁用选项', value: '12', disabled: true),
          ],
          onChange: (value) {
            print('选择：$value');
          },
        ),
        TDDropdownItem(
          maxHeight: 200,
          options: [
            TDDropdownItemOption(label: '选项1', value: '1', selected: true),
            TDDropdownItemOption(label: '选项2', value: '2'),
            TDDropdownItemOption(label: '选项3', value: '3'),
            TDDropdownItemOption(label: '选项4', value: '4'),
            TDDropdownItemOption(label: '选项5', value: '5'),
            TDDropdownItemOption(label: '选项6', value: '6'),
            TDDropdownItemOption(label: '选项7', value: '7'),
            TDDropdownItemOption(label: '选项8', value: '8'),
            TDDropdownItemOption(label: '选项9', value: '9'),
            TDDropdownItemOption(label: '禁用选项', value: '10', disabled: true),
            TDDropdownItemOption(label: '禁用选项', value: '11', disabled: true),
            TDDropdownItemOption(label: '禁用选项', value: '12', disabled: true),
          ],
        ),
      ];
    },
  );
}