将命令绑定到WPF中的ComboBoxItem

Question

I have a simple ComboBox that I want to trigger separate commands each time the selected value changes. Here is an example of my markup:

<WrapPanel Grid.Row="0" Visibility="{Binding ShowToggleViewFeedViewManual}">
    <ComboBox Margin="3,3,0,0">
        <ComboBoxItem IsEnabled="{Binding CanSelectViewFeedData}" >
            <ComboBoxItem.CommandBindings>
                <CommandBinding Command="SelectViewFeedDataCommand" />
            </ComboBoxItem.CommandBindings>
            <TextBlock Text="View Feed Data"/>
        </ComboBoxItem>
        <ComboBoxItem IsEnabled="{Binding CanSelectViewManualData}">
            <ComboBoxItem.CommandBindings>
                <CommandBinding Command="SelectManualFeedDataCommand" />
            </ComboBoxItem.CommandBindings>
            <TextBlock Text="View Manual Data"/>
        </ComboBoxItem>
    </ComboBox>
</WrapPanel>   

I get an error stating " Cannot convert 'SelectViewFeedDataCommand' ". I get a similar error for the other ComboBoxItem as well. The ICommand is defined in the ViewModel Class that is the DataSource for the UserControl, bound as a DataTemplate.

public ICommand SelectViewFeedDataCommand
{
    get
    {
        // Code to perform
    }
}

I have researched this pretty extensively but haven't found an answer for how to effectively bind the ICommand to the ComboBoxItem.

I am adapting this from existing code that used a set of radiobuttons and associated commands, which is done pretty easily. Is there no simple way to do this with a ComboBox?

Thanks.

Answer 1

Have you tried putting the command to a binding?

<CommandBinding Command="{Binding SelectManualFeedDataCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}}" />

Edit for updated strategy:

Since the ComboBox item doesn't support direct command binding, try creating an attached property:

Link

Answer 2

I was looking at my old posts and realized that I never posted the solution to my question... pretty simple really (if not elegant). I just created a List in my ViewModel that contained my Combo Box "choices" and then when the SelectedValue was changed, triggered my "changed" logic in the setter for the property:

<WrapPanel Grid.Row="0" Visibility="{Binding ShowToggleFeedViewManual}" >
    <ComboBox Margin="10,10,10,10" Width="200" ItemsSource="{Binding AvailableDataSources}" SelectedValue="{Binding SelectedDataSource}"/>
</WrapPanel>

And from the view-model:

public FeedSource SelectedDataSource
    {
        get { return _selectedDataSource; }
        set
        {
            _selectedDataSource = value;
            base.OnPropertyChanged("SelectedDataSource");

            //additional code to perform here

        }
    }