在多种条件下过滤不起作用

Question

我正在编写一个将虚拟数据加载到数据网格的 WPF 应用程序。数据网格包含以下数据模型：public class CharacterCollection  {    public string Name { get; set; }    public int Level { get; set; }    public string Race { get; set; }    public string Class { get; set; }    public List<CharacterCollection> GetCharacters()    {      List<CharacterCollection> characters = new List<CharacterCollection>();      characters.Add(new CharacterCollection { Name = "Lothar", Class = "Fighter", Race = "Human", Level = 5 });      characters.Add(new CharacterCollection { Name = "Turk", Class = "Barbarian", Race = "Half-Orc", Level = 3 });      characters.Add(new CharacterCollection { Name = "Melian", Class = "Cleric", Race = "Elf", Level = 10 });      //... there's about 16 more entries, but you get the idea ;)      return characters;    }接下来，我添加了 4 个组合框；每个都填充了 CharacterCollection 中的一个属性public partial class MainWindow : Window{    private CharacterCollection _characters = new CharacterCollection();    List<CharacterCollection> collection = new List<CharacterCollection>();    public MainWindow()    {      InitializeComponent();      collection = _characters.GetCharacters();      dgCharacterChart.ItemsSource = collection;      var characterNames = collection.Select(c =>c.Name).Distinct().ToList();      foreach(var item in characterNames)      {        CheckBox cb = new CheckBox();        cb.Content = item.ToString();        cbName.Items.Add(cb);      }      //...the other 3 combo boxes are filled the same way. I know its ugly and I will work on abstracting this a little better :)   }}到目前为止，我得到的是 4 个组合框，其中填充了复选框，用户可以根据需要进行检查。这些将用于过滤。当我单击仅选择一个字段的按钮时，例如从“名称”组合框中，它过滤得很好。但是，如果我从Name 中选择了多个，或者如果我开始检查其他组合框中的多个条目，则我的数据网格显示为空白。当我调试我的代码时，我可以看到我的谓词列表包含我所有标记为已检查的条目，但我的集合计数为 0。有人可以帮我弄清楚为什么我会得到这些结果吗？

Answer 1

我做了类似的事情，但我通过文本框过滤。也许它会帮助你。

.Xaml 如下

 <TextBox FocusManager.FocusedElement="{Binding RelativeSource={RelativeSource Self}}"

                                     Background="{x:Null}"

                                     Text="{Binding Item , UpdateSourceTrigger=LostFocus}" Margin="6,0,0,0" BorderThickness="0" PreviewKeyDown="ItemField_PreviewKeyDown" TextChanged="ItemField_TextChanged" IsReadOnly="{Binding IsReadonly}" />

.Xaml.cs 如下

private ObservableCollection<ItemGrid> _itemGrid = new ObservableCollection<ItemGrid>();

    public ObservableCollection<ItemGrid> ItemGrid

    {

        get

        {

            return _itemGrid;

        }

        set

        {

            _itemGrid = value;

        }

    }

    private void ItemField_TextChanged(object sender, TextChangedEventArgs e)

    {

        if (isBeginingEdit) return;

        //here we show the item selector and take care of autocomplete

        var textBox = sender as TextBox;

        if (textBox.Text != "")

        {

            var _itemSourceList = new CollectionViewSource() { Source = ItemGrid };

            ICollectionView Itemlist = _itemSourceList.View;

            ItemSearchText = textBox.Text;

            Itemlist.Filter = ItemFilter;

            var count = _itemSourceList.View.Cast<ItemGrid>().Count();

            if (count > 0)

            {

                ItemsGrid.ItemsSource = Itemlist;

            } 

        } 

   }