Binding Command to ViewModel inside UserControl

Question

I want to bind a UserControl to a ViewModel to use Commands/Events. My application consists of a MainWindow with a ContentControl inside, which is used to display a UserControls (the actual content) for navigation purposes.

MainWindow.xaml

<Window>
    <Window.Resources>
        <DataTemplate DataType="">
            <View: />
        </DataTemplate>
    </Window.Resources>
    <Menu>
        <MenuItem Header="Connection" Command="..." />
    </Menu>
    <Grid>
        <ContentControl Content="{Binding SelectedViewModel}" />
    </Grid>
</Window>

MainViewModel.cs

class MainViewModel : ViewModelBase {
    public ICommand MenuCommand;

    private object _SelectedViewModel;

    public object SelectedViewModel
    {
        get { return _SelectedViewModel; }
        set
        {
            _SelectedViewModel = value;
            RaisePropertyChanged("SelectedViewModel");
        }
    }

    public MainViewModel()
    {
        ICommand = new RelayCommand(MenuClick);
    }

    private void MenuClick(object obj)
    {
        SelectedViewModel = new ConnectionViewModel();
    }
}

This is how the navigation of my app works. The only problem I'm having is that I can't seem to use Commands ( Button for example) in the UserControl itself.

ConnectionView.xaml

<UserControl>
    <Grid>
        <Button Command="{Binding ButtonCommand}" Content="Button" />
    </Grid>
</UserControl>

ConnectionViewModel.cs

class ConnectionViewModel : ViewModelBase {
    public ICommand ButtonCommand;

    public ConnectionViewModel()
    {
        ButtonCommand = new RelayCommand(ButtonClick);
    }

    private void ButtonClick(object obj)
    {
        MessageBox.Show("Clicked");
    }
}

I can fill ListViews in the UserControl View but I can't get the Button Command working. What exactly is the problem, where did I go wrong?

Answer 1

ButtonCommand must be a property for you to be able to bind to it:

public ICommand ButtonCommand { get; private set; }

You have defined it as a field:

public ICommand ButtonCommand;