如何在ui-select中设置默认值

<ui-select ng-model="selectedItem">
  <ui-select-match>{{$select.selected.name}}</ui-select-match>
  <ui-select-choices repeat="item in items">
    <div>{{item.name}}</div>
  </ui-select-choices>
</ui-select>

$scope.selectedItem = { name: '默认值' };

$scope.items = [
  { name: '默认值' },
  { name: '选项1' },
  { name: '选项2' },
  { name: '选项3' }
];

<ui-select ng-model="selectedItem" ng-init="selectedItem = items[0]">
  <!-- 下拉列表的其他代码 -->
</ui-select>