通过文本框从列表框中过滤元素

Question

您已经创建了一个绑定到机器列表的列表框。由于机器数量可能急剧增加，我需要按名称过滤。出于这个原因，我提供了一个TextBox，用户可以引入一个字符串来过滤掉。 我想创建另一个列表，它将绑定到视图，即第二个列表仅用于可视化。但是，我认为必须有一个更干净的方式来做到这一点。

<ListBox IsSynchronizedWithCurrentItem="True" Visibility="{Binding MachinesPanelVisibility}" 
        ItemsSource="{Binding MachineRulesList}" SelectedIndex="{Binding ItemSelectionIndex}" /> 

<TextBox HorizontalAlignment="Right" Width="162" Text="Filter..." TextWrapping="Wrap" Margin="0,44,18,13" /> 

在视图模型：

public class BusinessRulesWizardViewModel : INotifyPropertyChanged 
    { 

public ObservableCollection<string> MachineRulesList 
    { 
     get { return _machineRulesList; } 
     set 
      { 
      _machineRulesList = value; 
      OnPropertyChanged("MachineRulesList"); 
      } 
     } 



public BusinessRulesWizardViewModel(ISystemView systemViewManager, 
     IEventAggregator eventAggregator) 
    { 
     _machineRulesList = new ObservableCollection<string>(); 
     _systemViewManager.GetMachines(page, pageSize).ToList().ForEach(
      item => _machineRulesList.Add(item) 
     ); 
    } 

Answer 1

使用可以使用ICollectionView接口与Filter属性设置为使用在TextBox输入的文本谓词来包装你的收藏。这里有一个例子：

<ListBox IsSynchronizedWithCurrentItem="True" Visibility="{Binding MachinesPanelVisibility}" 
     ItemsSource="{Binding MachineRulesListView}" 
     SelectedIndex="{Binding ItemSelectionIndex}" /> 
<TextBox HorizontalAlignment="Right" Width="162" 
     Text="{Binding FilterText}" 
     TextWrapping="Wrap" Margin="0,44,18,13" /> 

-

public class BusinessRulesWizardViewModel : INotifyPropertyChanged 
{ 

    public ObservableCollection<string> MachineRulesList 
    { 
     get { return _machineRulesList; } 
     set 
      { 
      _machineRulesList = value; 
      OnPropertyChanged("MachineRulesList"); 
      } 
    } 

    public string FilterText 
    { 
     get { return _filterText; } 
     set 
      { 
      _filterText= value; 
      OnPropertyChanged("FilterText"); 
      MachineRulesListView.Refresh(); 
      } 
    } 

    public ICollectionView MachineRulesListView { get; private set; } 



    public BusinessRulesWizardViewModel(ISystemView systemViewManager, IEventAggregator eventAggregator) 
    { 
     _machineRulesList = new ObservableCollection<string>(); 
     MachineRulesListView = CollectionViewSource.GetDefaultView(_machineRulesList); 
     MachineRulesListView.Filter = new Predicate<object>(r => ((string)r).Contains(FilterText)); 

     _systemViewManager.GetMachines(page, pageSize).ToList().ForEach(
      item => _machineRulesList.Add(item) 
     ); 
    } 
}