wpf中treeview和ICollectionView接口实现数据过滤

    private ICollectionView _collectionView;
    private void binddata(List<obj> list)
    {
        // 创建CollectionViewSource并绑定到TreeView
        CollectionViewSource collectionViewSource = new CollectionViewSource
        {
            Source = list
        };
        Treeview.ItemsSource = collectionViewSource.View;
        _collectionView = collectionViewSource.View;
    }
//搜索文本框去
      private void TextBox_Changed(object sender, RoutedEventArgs e)
      {
          string filterText = Keyword.Text;

          // 设置过滤方法
          _collectionView.Filter = item =>
          {
              obj category = (obj )item;
              bool isfilter = false;

              if (category.children.Count != 0)
              {
                  isfilter = category.children.Any(x => x.label.Contains(filterText));
              }
              if (category.label.Contains(filterText))
              {
                  isfilter = true;
              }//多层级的使用两个if去过滤这个没过上一层可以过，这里可以做成递归
              return isfilter;
          };

          // 强制刷新视图
          _collectionView.Refresh();
      }