C# WPF ListBox Checkbox Binding IsChecked to a Fie

Question

I'm trying to bind a CheckBox to a field but also trigger the checkbox's IsSelected.

Here is the ListBox setup that is working with the Binding to data

<ListBox x:Name="lstExclude"  Grid.Column="2" SelectionMode="Single" >
  <ListBox.ItemTemplate>
    <DataTemplate>
      <CheckBox  Content="{Binding Text}" 
          IsChecked="{Binding Checked ,Mode=TwoWay}"/>
      </DataTemplate>
  </ListBox.ItemTemplate>
</ListBox>

And here is the code associated with the binding

public MainWindow()
{
    InitializeComponent();

    List<CheckBoxListItem> items1 = new List<CheckBoxListItem>();
    items1.Add(new CheckBoxListItem(true, “home”));
    items1.Add(new CheckBoxListItem(false, “work”));
    items1.Add(new CheckBoxListItem(true, “cell”));
    lstExclude.ItemsSource = items1;
}

public class CheckBoxListItem
{
   public bool Checked { get; set; }
   public string Text { get; set; }

   public CheckBoxListItem(bool ch, string text)
   {
     Checked = ch;
     Text = text;
    }
}

This binds the checkbox checked value correctly, but if I click the checkbox (checked or unchecked), I want it to select the item, so I tried doing it this way

<ListBox x:Name="lstExclude"  Grid.Column="2" SelectionMode="Single" >
  <ListBox.ItemTemplate>
    <DataTemplate>
      <CheckBox  Content="{Binding Text}" 
          IsChecked="{Binding RelativeSource={RelativeSource AncestorType=ListBoxItem}, Path=IsSelected}"/>
      </DataTemplate>
  </ListBox.ItemTemplate>
</ListBox>

So this gives me the results of clicking the checkbox (check or uncheck) and it will select the item. The problem is now the Checked field is not bound when I add the items.

How can you get the checkbox to be both bound to the Checked field AND still have the IsSelected work?

Answer 1

you can use a MultiBinding with MultiConverter

<CheckBox.IsChecked>
<MultiBinding Converter="{StaticResource YourMultiBindConverter}"> 
                <Binding Path="IsSelected" RelativeSource={RelativeSource AncestorType=ListBoxItem}"/> 
                <Binding Path="Checked"/> 
 </MultiBinding> 
</CheckBox.IsChecked>

and create a YourMultiBindConverter that implement IMultiValueConverter

Answer 2

 <CheckBox Padding="10" 
           IsChecked="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type  
                                                 ListBoxItem}}, Path=IsSelected}">
        <CheckBox.LayoutTransform>
                  <ScaleTransform ScaleX="1" ScaleY="1" />
        </CheckBox.LayoutTransform>
  </CheckBox>

Answer 3

Would it work to bind both UI properties to the Checked object model property?

<ListBox.ItemContainerStyle>
    <Style TargetType="{x:Type ListBoxItem}">
        <Setter Property="IsSelected" Value="{Binding Checked, Mode=OneWay}"/>
    </Style>
</ListBox.ItemContainerStyle>

<ListBox.ItemTemplate>
   <DataTemplate>
      <CheckBox Content="{Binding Text}" IsChecked="{Binding Checked}"/>
   </DataTemplate>
</ListBox.ItemTemplate>

Answer 4

Ok, I answered my own question (and there might better to do this so feel free to add) I added a Click event to the checkbox like so

<ListBox x:Name="lstExclude"  Grid.Column="2" SelectionMode="Single" >
 <ListBox.ItemTemplate>
    <DataTemplate>
      <CheckBox  Content="{Binding Text}" 
          IsChecked="{Binding Checked ,Mode=TwoWay}" Click="CheckBox_Click"/>
      </DataTemplate>
 </ListBox.ItemTemplate>
</ListBox>

and then added this code for the Click Event

private void CheckBox_Click(object sender, RoutedEventArgs e)
{
    var cb = sender as CheckBox;
    var item = cb.DataContext;
    lstExclude.SelectedItem = item;
}

Now the item gets selected when you click the checkbox (checked or unchecked) and the item is available to the 'lstExclude.SelectedIndex' method

I hope this helps anybody coming along with the same problem.