StackPanel 的可见性（在 ItemsControl 内）可以由按钮控制吗？

Question

I have a property List<Filter> Filters which is the ItemSource of an ItemsControl . What I am trying to accomplish is to show at the beginning only the filters which have the property IsShown = true . Then, when I push the button, to show the rest of the filters. Is it possible to be done using XAML? If no, which approach should I use?

The content of the Filter class is:

        public List<string> Options { get; set; } = new List<string>();
        public bool IsShown { get; set; }
        public string Title { get; set; }
        public string ValueSelected { get; set; }

        public Filter(List<string> Options, string Title, string ValueSelected, bool IsShown)
        {
            this.Options = Options;
            this.Title = Title;
            this.ValueSelected = ValueSelected;
            this.IsShown = IsShown;
        }

In MainContext I have defined the List and a button:

        public ObservableCollection<Filter> Filters { get; set; } = new ObservableCollection<Filter>();
        public ICommand DoShowHide

In MainWindow.XAML at this point I have the following:

            <ItemsControl ItemsSource="{Binding Filters}">
                <ItemsControl.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Vertical" Visibility="{Binding Path=IsShown, Converter={StaticResource BoolToVisConverter} }" Name="MyStackPanel">
                            <TextBlock Text="{Binding Title}"/>
                            <ComboBox ItemsSource="{Binding Path=Options}"
                              SelectedValue="{Binding Path=ValueSelected}" />
                        </StackPanel>
                    </DataTemplate>
                </ItemsControl.ItemTemplate>
            </ItemsControl>
            <Button Content="Show/Hide" Command="{Binding DoShowHide}"/>

with the mentioning that I have defined the converter

<Window.Resources>
   <BooleanToVisibilityConverter x:Key="BoolToVisConverter" />
</Window.Resources>

****I have tried to set all the filters' IsShown property to true at the push of the button. No need to mention that it did not work...

        private void ShowHide(object obj)
        {
            MessageBox.Show("message");
            foreach(Filter filter in Filters)
            {
                if(filter.IsShown == false)
                {
                    filter.IsShown = true;
                    NotifyPropertyChanged("Filters");
                }
            }
        }

Thank you for taking the time to read my question:)

Answer 1

you can make it using converter where you return the a visibility object

Answer 2

Your Filter class must implement INotifyPropertyChanged . Otherwise property changes inside this class are not propagated to the binding system.

Raising the ProperyChanged event on the Filters property, as you did, is useless.

Note: you can use XOR operation to toggle boolean values (show/hide).

Shortened Filter class:

class Filter : INotifyPropertyChanged
{       
  private bool isDisplayed
  public bool IsDisplayed
  {
    get => this.isDisplayed;
    set
    {
      if (value != this.isDisplayed)
      {
        this.isDisplayed = value;
        OnPropertyChanged();
      }
    }
  }

  public event PropertyChangedEventHandler PropertyChanged;

  private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
  { 
    this.PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));        
  }
}

The shortened DataTemplate for the Filter item:

<DataTemplate DataType="{x:Type Filter}">
  <StackPanel Visibility="{Binding IsDisplayed, Converter={StaticResource BoolToVisibilityConverter}}">

  </StackPanel>
</DataTemplate>

The modified ICommand execution handler:

private void ShowHide(object obj)
{
  // Toggle all Filter.IsDisplayed
  foreach (Filter filter in Filters)
  {
    filter.IsDisplayed ^= true;
  }
}