筛选/搜索绑定的列表框

Question

Hej，

我得到了一个绑定到ObservableCollection的ListBox，现在我正试图实现一个搜索/筛选函数。但它不起作用。。。什么都试过了：(

这是我的列表框的图片https://i.stack.imgur.com/SuNZS.png

好的，多亏了Maximus的链接，我得到了解决方案。我更新了我的代码

这就是我迄今为止尝试的.xaml代码

 <ListBox Name="lstWarning" Margin="-14,3,-31,-30">
    <ListBox.ItemTemplate>
        <DataTemplate>
            <Canvas Height="62" Width="582">
                <Label Foreground="#FFA8A4A4" FontFamily="{DynamicResource HeaderFontFamily}" FontSize="11" Content="{Binding DirName}" Canvas.Left="39" Canvas.Top="23"/>
                <Label Foreground="#FFA8A4A4" FontFamily="{DynamicResource HeaderFontFamily}" FontSize="11" Content="{Binding CreationDate}" Canvas.Left="39" Canvas.Top="40"/>
                <Label Foreground="White" FontFamily="{DynamicResource HeaderFontFamily}" FontSize="14" Content="{Binding FileName}" Canvas.Left="39" Canvas.Top="4"/>
                <Label Foreground="#FFA8A4A4" FontFamily="{DynamicResource HeaderFontFamily}" FontSize="11" Content="{Binding Extension}" Canvas.Left="224" Canvas.Top="40"/>
                <Label Foreground="#FFA8A4A4" FontFamily="{DynamicResource HeaderFontFamily}" FontSize="11" Content="{Binding FileSize}" Canvas.Left="155" Canvas.Top="40"/>
                <Image Source="{Binding StatusImage}" Width="30" Height="30" Canvas.Left="10" Canvas.Top="6" Stretch="Fill"/>
            </Canvas>
        </DataTemplate>
    </ListBox.ItemTemplate>
 </ListBox>

下面是如果在TextChanged事件中执行的操作

private void cmdSearchWarnings_TextChanged(object sender, System.Windows.Controls.TextChangedEventArgs e) {
        CollectionView cv = (CollectionView)CollectionViewSource.GetDefaultView(lstWarning.ItemsSource);
        if (!string.IsNullOrEmpty(txtSearchWarnings.Text)) {

            if (isFilter) {
                cv.Filter = null;
                isFilter = false;   
            }
            else {
                cv.Filter = new Predicate<object>(FilterByFileName);
                isFilter = true;
            }
        }
        else {
            cv.Filter = null;
            isFilter = false;
        }
    }
    private bool FilterByFileName(object _warningObj) {
        if (_warningList != null) {
            if (!string.IsNullOrEmpty(txtSearchWarnings.Text)) {
                var warning = _warningObj as WarningItem;
                return warning.FileName.Trim().Contains(txtSearchWarnings.Text);
            }
        }
        return false;
    }

这是我的警告项目类别代码：

public class WarningItem
{
    public string FullPath { get; set; }
    public string DirName { get; set; }
    public string FileName { get; set; }
    public string FileSize { get; set; }
    public string CreationDate { get; set; }
    public string Extension { get; set; }
    public Uri StatusImage { get; set; }
}

Answer 1

我正在粘贴一个简单的例子，但类似的例子已经被覆盖了无数次，你需要深入研究SO。下面的例子检查集合Names是否包含元素，而元素又包含搜索词。

private ObservableCollection<string> _names = new ObservableCollection<string>()
    {
        "Isabel", "Michal"
    };
    public ObservableCollection<string> Names
    {
        get { return _names; }
        set { _names = value; }
    }
    private ICollectionView View;
    public MainWindow()
    {
        InitializeComponent();
        ListBox.ItemsSource = Names;
        View = CollectionViewSource.GetDefaultView(Names);
    }
    private void TextBoxBase_OnTextChanged(object sender, TextChangedEventArgs e)
    {
        View.Filter = x => x.ToString().ToLower().Contains(((TextBox)sender).Text.ToLower());
    }

不需要在TextBoxChanged事件中调用CollectionViewSource.GetDefaultView(Names(，因为collectionView只检索一次并保持引用。看看这里

如果涉及到MVVM模式，您不应该使用so后面的代码而不是

<TextBox TextChanged="TextBoxBase_OnTextChanged"/>

你应该有

  <TextBox Text="{Binding FilterText}">
        <i:Interaction.Triggers>
            <i:EventTrigger EventName="TextChanged">
                <i:InvokeCommandAction Command="{Binding FilterListCommand}"/>
            </i:EventTrigger>
        </i:Interaction.Triggers>
    </TextBox>

RelayCommand