wpf - ContextMenu Command Binding para padres y para uno mismo

datagrid viewmodel

Question

Estoy intentando crear un ContextMenu en un DataGrid con múltiples Enlaces de Comandos. Algunos tienen que estar vinculados al ViewModel local (es decir, el ViewModel de la fila) y algunos a los padres ViewModel.

Hasta ahora no he tenido suerte siguiendo otras soluciones. Solo obtengo el Subcomando para ejecutar.

MainViewModel

public class MainViewModel : ViewModelBase
{
    public ObservableCollection<SubViewModel> Items { get; private set; } 

    public MainViewModel()
    {

        Items = new ObservableCollection<SubViewModel>();

        Items.Add(new SubViewModel());
        Items.Add(new SubViewModel());
    }

    private RelayCommand _mainCommand;

    public ICommand MainCommand
    {
        get
        {
            if (_mainCommand == null)
            {
                _mainCommand = new RelayCommand(
                    () =>
                        {
                            Debug.WriteLine("MAINCOMMAND EXECUTED");
                        }
                    );
            }
            return _mainCommand;
        }
    }
}

SubViewModel

public class SubViewModel : ViewModelBase
{
    private RelayCommand _subCommand;

    public ICommand SubCommand
    {
        get
        {
            if (_subCommand == null)
            {
                _subCommand = new RelayCommand(
                    () =>
                        {
                            Debug.WriteLine("SUBCOMMAND EXECTUED");
                        }
                    );
            }
            return _subCommand;
        }
    }
}

Ventana principal

<Window x:Class="WpfApplication4.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"
        Width="525"
        Height="350"
        DataContext="{Binding Source={StaticResource Locator},
                              Path=Main}">
    <Grid>
        <DataGrid ItemsSource="{Binding Items}">

            <DataGrid.RowStyle>
                <Style TargetType="{x:Type DataGridRow}">
                    <Setter Property="ContextMenu">
                        <Setter.Value>
                            <ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
                                <MenuItem Command="{Binding DataContext.MainCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ContextMenu}}}" Header="Main" />
                                <MenuItem Command="{Binding SubCommand}" Header="Sub" />
                            </ContextMenu>
                        </Setter.Value>
                    </Setter>
                </Style>
            </DataGrid.RowStyle>

        </DataGrid>
    </Grid>
</Window>

Answer 1

He encontrado una manera, pero no creo que sea demasiado elegante, tal vez haya una mejor manera, pero esto funcionará:

<Window x:Class="WpfApplication4.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow"
        Width="525"
        Height="350"
        DataContext="{Binding Source={StaticResource Locator},
                              Path=Main}">
    <Grid x:Name="Grid">
        <DataGrid x:Name="DataGrid" ItemsSource="{Binding Items}">

            <DataGrid.RowStyle>
                <Style TargetType="{x:Type DataGridRow}">

                    <Setter Property="ContextMenu">
                        <Setter.Value>
                            <ContextMenu>
                                <MenuItem Command="{Binding Path=PlacementTarget.Tag.MainCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type ContextMenu}}}" Header="Main" />
                                <MenuItem Command="{Binding SubCommand}" Header="Sub" />
                            </ContextMenu>
                        </Setter.Value>
                    </Setter>

                    <Setter Property="Tag" Value="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type DataGrid}}, Path=DataContext}" />
                </Style>
            </DataGrid.RowStyle>

        </DataGrid>
    </Grid>
</Window>