I have an object consisting of a string and a string of arrays. I'm binding the string to a comboBox but what I want to also do is bind the array of that object to a listview and have it change dynamically depending on combox box value. The values in the array aren't populating, only the dataType of the array. I'm not married to using a listview but I thought it would be easiest.

Model -

namespace DataBinding_WPF.Model
{
    public class ExampleModel { }

    public class Example : INotifyPropertyChanged
    {
        private string _name;
        private string[] _ids;

        public string Name
        {
            get => _name;
            set
            {
                if (_name != value)
                {
                    _name = value;
                    RaisePropertyChanged("Name");
                }
            }
        }

        public string[] IDs
        {
            get => _ids;
            set
            {
                if (_ids != value)
                {
                    _ids = value;
                    RaisePropertyChanged("IDs");
                }
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string property)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged(this, new 
                    PropertyChangedEventArgs(property));
            }
        }
    }

ViewModel -

namespace DataBinding_WPF.ViewModel
{
    public class ExampleViewModel
    {
        public ObservableCollection<Example> Examples
        {
            get;
            set;
        }

        public void LoadExample()
        {
            ObservableCollection<Example> examples = new ObservableCollection<Example>();
            examples.Add(new Example { Name = "Mark", IDs = new string[] { "123", "456" }});
            examples.Add(new Example { Name = "Sally", IDs = new string[] { "789","101112" }});
            Examples = examples;
        }
    }
}

XAML -

    <Grid>
        <StackPanel HorizontalAlignment = "Left" >

            <ComboBox HorizontalAlignment="Left"   
                  VerticalAlignment="Top"   
                  Width="120"   
                  ItemsSource="{Binding Path=Examples}"    
                  SelectedItem="{Binding Path=Name, Mode=TwoWay}"  
                  DisplayMemberPath="Name"/>

            <ListView x:Name="myListView" 
                        ItemsSource="{Binding Path=Examples}"   
                        SelectedValue="{Binding Path=IDs}" 
                        Height="200" Margin="0,50,0,0" 
                              Width="Auto"
                        VerticalAlignment="Top"
                        Background="AliceBlue">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal" >
                            <CheckBox 
                                    Name="myCheckBox"                            
                                    IsChecked="{Binding IsSelected,
                                        RelativeSource={RelativeSource AncestorType=ListViewItem}}"
                                        Margin="5, 0"/>
                            <TextBlock Text= "{Binding Path=IDs}" FontWeight="Bold" />
                        </StackPanel>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
        </StackPanel>
    </Grid>

CodePudding user response：

There could several solutions to your case but most common and proprietary way is to use ValueConverter.

For this example i'll assume you have grid in the Window control. You need to add static resource:

<Window.Resources>
    <local:ArrayValueConverter x:Key="arrayConverter"/>
</Window.Resources>

Then in your ListView's DataTemplate add Converter:

<TextBlock Text= "{Binding Path=IDs, Converter={StaticResource arrayConverter}}" FontWeight="Bold" />

ValueConverter himself:

public class ArrayValueConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value is string[] arr) {
            return string.Join(',', arr);
        }

        return value;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return value;
    }
}

CodePudding user response：

If you want to show in ListBox the Ids of selected item in comboBox. You need to add SelectedItem property to your VM which also must implement INotifyPropertyChanged interface.

namespace DataBinding_WPF.ViewModel
{
    public class ExampleViewModel : INotifyPropertyChanged
    {
        public ObservableCollection<Example> Examples
        {
            get;
            set;
        }

        // SelectedItem in the ComboBox
        // SelectedItem.Ids will be ItemsSource for the ListBox
        private Example _selectedItem;
        public Example SelectedItem
        {
          get => _selectedItem;
          set {
              _selectedItem = value;
              OnPropertyChanged(nameof(SelectedItem));
          } 
        }

        // SelectedId in ListView
        private string _selectedId;
        public string SelectedId
        {
          get => _selectedId;
          set {
              _selectedId= value;
              OnPropertyChanged(nameof(SelectedId));
          } 
        }
         
        public void LoadExample()
        {
            ObservableCollection<Example> examples = new ObservableCollection<Example>();
            examples.Add(new Example { Name = "Mark", IDs = new string[] { "123", "456" }});
            examples.Add(new Example { Name = "Sally", IDs = new string[] { "789","101112" }});
            Examples = examples;
        }
    }
}

XAML

<Grid>
        <StackPanel HorizontalAlignment = "Left" >

            <ComboBox HorizontalAlignment="Left"   
                  VerticalAlignment="Top"   
                  Width="120"   
                  ItemsSource="{Binding Path=Examples}"    
                  SelectedItem="{Binding SelectedItem}"  
                  DisplayMemberPath="Name"/>

            <ListView x:Name="myListView" 
                        ItemsSource="{Binding SelectedItem.Ids}"   
                        SelectedItem="{Binding SelectedId}" 
                        Height="200" Margin="0,50,0,0" 
                              Width="Auto"
                        VerticalAlignment="Top"
                        Background="AliceBlue">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal" >
                            <CheckBox 
                                    Name="myCheckBox"                            
                                    IsChecked="{Binding IsSelected,
                                        RelativeSource={RelativeSource AncestorType=ListViewItem}}"
                                        Margin="5, 0"/>
                            <TextBlock Text= "{Binding}" FontWeight="Bold" />
                        </StackPanel>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
        </StackPanel>
    </Grid>