フィルタリングリスト表示が表示されない

Question

私のTextBoxに基づいてListViewをフィルタリングしようとしていますが、何らかの理由で発砲していません。デバッガを実行すると、変更する入力テキストが表示されますが、ListViewには反映されません。

私のメインビューモデル：

 projectCollection = new CollectionViewSource(); 
     projectCollection.Source = Projects; 
     projectCollection.Filter += projectCollection_Filter; 
    } 

    public ICollectionView SourceCollection 
    { 
     get 
     { 
      return this.projectCollection.View; 
     } 
    } 

    public string FilterText 
    { 
     get 
     { 
      return filterText; 
     } 
     set 
     { 
      filterText = value; 
      this.projectCollection.View.Refresh(); 
      RaisePropertyChanged("SearchProjectsText"); 
     } 
    } 

    private void projectCollection_Filter(object sender, FilterEventArgs e) 
    { 
     if (string.IsNullOrEmpty(FilterText)) 
     { 
      e.Accepted = true; 
      return; 
     } 

     Project project = e.Item as Project; 
     if (project.Name.ToUpper().Contains(FilterText.ToUpper()) || project.Path.ToUpper().Contains(FilterText.ToUpper())) 
     { 
      e.Accepted = true; 
     } 
     else 
     { 
      e.Accepted = false; 
     } 
    } 

    public void RaisePropertyChanged(string propertyName) 
    { 
     if (this.PropertyChanged != null) 
     { 
      this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
     } 
    } 
} 

}

そして、私の関連するXAML：

<TextBox x:Name="SearchProjectsBox" Grid.Column="5" Background="White" Grid.Row="1" Text="{Binding FilterText, UpdateSourceTrigger=PropertyChanged}" 
     Margin="47.333,0,0,654.333" VerticalContentAlignment="Center" Foreground="Black" Padding="6" FontSize="16" HorizontalAlignment="Left" Width="268"/> 

       <ListView x:Name="ProjectListView" Margin="0,0,10,0" ItemsSource="{Binding ElementName=Hierarchy, Path=SelectedItem.GetAllMembers, UpdateSourceTrigger=PropertyChanged}" FontSize="16" Foreground="Black"> 

編集。ここにXAMLがあります。

<TextBox x:Name="SearchProjectsBox" Grid.Column="5" Background="White" Grid.Row="1" Text="{Binding FilterText, UpdateSourceTrigger=PropertyChanged}" 
     Margin="47.333,0,0,654.333" VerticalContentAlignment="Center" Foreground="Black" Padding="6" FontSize="16" HorizontalAlignment="Left" Width="268"/> 
    <TreeView x:Name="Hierarchy" Grid.Column="4" HorizontalAlignment="Left" Height="631" Margin="0,58,0,0" Grid.Row="1" VerticalAlignment="Top" Width="226" 
       ItemsSource="{Binding Path=Projects}"> 
     <TreeView.ItemTemplate> 
      <HierarchicalDataTemplate ItemsSource="{Binding ChildFolders}"> 
       <StackPanel Orientation="Horizontal" > 
        <Image Source="{Binding Icon}" MouseUp="SelectedFolder_Event" Margin="5, 5, 5, 5"></Image> 
        <TextBox x:Name="FolderNames" Text="{Binding Name, UpdateSourceTrigger=PropertyChanged, Mode=TwoWay}" BorderThickness="0" FontSize="16" Margin="5" IsReadOnly="True" PreviewMouseDoubleClick="SelectAll" LostFocus="TextBoxLostFocus"/> 
       </StackPanel> 
      </HierarchicalDataTemplate> 
     </TreeView.ItemTemplate> 
    </TreeView> 

次に、私のView Modelテンプレートを示します。

private ObservableCollection<Project> projects; 
    private string filterText; 
    private CollectionViewSource projectCollection; 
    public event PropertyChangedEventHandler PropertyChanged; 
    public ObservableCollection<Project> Projects 
    { 
     get { return projects; } 
     set 
     { 
      if (value != projects) 
      { 
       projects = value; 
       OnPropertyChanged("Projects"); 
      } 
     } 
    } 

    public string FilterText 
    { 
     get 
     { 
      return filterText; 
     } 
     set 
     { 
      filterText = value; 
      this.projectCollection.View.Refresh(); 
      OnPropertyChanged("SearchProjectsText"); 
     } 
    } 

    private void projectCollection_Filter(object sender, FilterEventArgs e) 
    { 
     if (string.IsNullOrEmpty(FilterText)) 
     { 
      e.Accepted = true; 
      return; 
     } 

     Project project = e.Item as Project; 
     if (project.Name.ToUpper().Contains(FilterText.ToUpper()) || project.Path.ToUpper().Contains(FilterText.ToUpper())) 
     { 
      e.Accepted = true; 
     } 
     else 
     { 
      e.Accepted = false; 
     } 
    } 

    public void OnPropertyChanged(string propertyName) 
    { 
     if (this.PropertyChanged != null) 
     { 
      this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); 
     } 
    } 

上記のメソッドは、TextBoxのテキストに基づいてリストビューをフィルタリングおよび更新するために使用されるメソッドです。

Answer 1

CollectionViewでフィルタを使用する簡単な例。下記のコードを参照してください。

<Grid > 
    <StackPanel> 
     <StackPanel Orientation="Horizontal"> 
      <TextBlock Text="Filter"/> 
      <TextBox Text="{Binding TextValue, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" Width="200"/> 
     </StackPanel> 
     <ListBox ItemsSource="{Binding EmpView}" DisplayMemberPath="Name"/> 
    </StackPanel> 

</Grid> 

class ViewModel : INotifyPropertyChanged 
{ 
    private string myVar; 

    public string TextValue 
    { 
     get { return myVar; } 
     set { myVar = value; 
      OnPropertyChanged("TextValue"); EmpView.Refresh();} 
    } 

    public ICollectionView EmpView { get; set; } 
    public List<Employee> Employees { get; set; } 
    public ViewModel() 
    { 
     Employees = new List<Employee>() 
     { 
      new Employee() {Name = "Test1"}, 
      new Employee() {Name = "Version2"}, 
      new Employee() {Name = "Test2"}, 
      new Employee() {Name = "Version4"}, 
      new Employee() {Name = "Version5"} 
     }; 
     EmpView = CollectionViewSource.GetDefaultView(Employees); 
     EmpView.Filter = Filter; 
    } 

    private bool Filter(object emp) 
    { 
     if (string.IsNullOrWhiteSpace(TextValue)) 
     { 
      return true; 
     } 
     var emp1 = emp as Employee; 
     return TextValue != null && (emp1 != null && emp1.Name.Contains(TextValue)); 
    } 


    public event PropertyChangedEventHandler PropertyChanged; 

    protected virtual void OnPropertyChanged(string propertyName) 
    { 
     PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName)); 
    } 
} 

class Employee 
{ 
    public string Name { get; set; } 
}