How to add the same command to WPF buttons in ItemsControl

Question

How would you add command to a wpf button that is part of ItemsControl and is modifying the ItemsSource itself?

So here is my XAML:

<ItemsControl ItemsSource="{Binding PluginVMs}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <Button x:Name="btnStampDuplicate" 
                        Content="Duplicate this control"
                        Command="{Binding ?????????}"/>
                <!-- other stuff -->
            </StackPanel>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

And here is my viewmodel:

public ObservableCollection<PluginViewModel> PluginVMs
{
    get { return _pluginVMs; }
    set
    {
        if (_pluginVMs != value)
        {
            _pluginVMs = value;
            NotifyPropertyChanged("PluginVMs");
        }
    }
}

As you can see PluginVMs is collection of PluginViewModel. So I am aware that the Command that is available from the btnStampDuplicate should be implemented inside of PluginViewModel.

However, as the name duplicate suggest, I would like to make a duplicated copy of the currently generated PluginViewModel inside of PluginVMs. What is the best approach to give that kind of functionality to btnStampDuplicate?

Answer 1

it is not necessary to have a command in each item. you can use CommandParameter to pass an item which is a dupe source

inside DataTemplate bind command using ElementName to access DataContext of a higher level

View

<ItemsControl Name="ListPlugins" ItemsSource="{Binding PluginVMs}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <StackPanel>
                <Button x:Name="btnStampDuplicate" 
                        Content="duplicate"
                        CommandParameter={Binding Path=.}
                        Command="{Binding Path=DataContext.DupeCmd, ElementName=ListPlugins}"
                />
                <!-- other stuff -->
            </StackPanel>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

ViewModel

public class Vm
{
    public ObservableCollection<PluginViewModel> PluginVMs
    {
        get { return _pluginVMs; }
        set
        {
            if (_pluginVMs != value)
            {
                _pluginVMs = value;
                NotifyPropertyChanged("PluginVMs");
            }
        }
    }

    public ICommand DupeCmd { get; private set; }
}