Question

I’m currently working on a WPF application that uses MVVM. I’ve got a ListBox with a style set up to make it display like a RadioButtonList as follows:

<Style x:Key="RadioButtonList" TargetType="{x:Type ListBox}">
    <Setter Property="BorderBrush" Value="{x:Null}" />
    <Setter Property="BorderThickness" Value="0" />
    <Setter Property="ItemContainerStyle">
        <Setter.Value>
            <Style TargetType="{x:Type ListBoxItem}" >
                <Setter Property="Margin" Value="2" />
                <Setter Property="Template">
                    <Setter.Value>
                        <ControlTemplate TargetType="{x:Type ListBoxItem}">
                            <Border Background="Transparent">
                                <RadioButton Focusable="False" IsHitTestVisible="False" IsChecked="{TemplateBinding IsSelected}" Content="{Binding Path=DisplayName}" Command="{Binding ElementName=ShippingWindow, Path=DataContext.ShipOtherMethodSelected}">
                                </RadioButton>
                            </Border>
                        </ControlTemplate>
                    </Setter.Value>
                </Setter>
            </Style>
        </Setter.Value>
    </Setter>
</Style>

<ListBox Name="lbShipOtherMethodOptions" Style="{StaticResource RadioButtonList}" ItemsSource="{Binding Path=ShipOtherMethodOptions}" Margin="13,74,366,282" />

What I’m trying to do is bind a command to the RadioButton, so that I can fire off an event when a selection is made. I’ve got the following code in my viewmodel, but I can’t seem to get it to fire:

    private ICommand shipOtherMethodSelected;
    public ICommand ShipOtherMethodSelected
    {
        get
        {
            return shipOtherMethodSelected ??
                   (shipOtherMethodSelected = new RelayCommand(param => ShipOpenItems(), param => true));
        }
    }

    private void ShipOpenItems()
    {
        MessageBox.Show("GOT HERE");
    }

I’m pretty new to WPF and MVVM, so I’m probably missing something obvious. Can anyone point me in the right direction?

EDIT:
Per jberger’s suggestion, I put in some code that I attempted that didn’t work. Setting breakpoints in that section didn’t get tripped, nor did the message box show up.

EDIT 2:
So after inspecting the DataContext on the sender, it turns out it was pointing to the object that I’m binding the RadioButton to, and not my viewmodel. I updated the code above (adding in an x:Name to my window and updating the Command binding), and now I’m getting the event to fire when its initially bound, but it doesn’t fire when I select a value. Seems like we’re getting really close now.

Answer 1

The ShipOtherMethodSelected is in your (main) ShippingVM NOT your ShipItemVM, so you need to set

Command="{Binding ElementName=ShippingWindow, Path=DataContext.ShipOtherMethodSelected}"

where ShippingWindow is the x:Name of an element “above” the ListBoxItem

Also, the Focusable="False" IsHitTestVisible="False" is denying the click. Remove the setters.