Button will not work, unable to find suitable setter or getter

Question

public class MainWindowViewModel : ViewModelBase
{
    public MainWindowViewModel()
    {

        Queue = new QueuePanelViewModel();
        Merge = new MergePanelViewModel();

        CurrentQueuePanel ??= new QueuePanel();
        CurrentMergePanel ??= new MergePanel();
        _selectedView = CurrentQueuePanel;

    }

    public QueuePanelViewModel Queue { get; }
    public MergePanelViewModel Merge { get; }

    private UserControl _selectedView;
    public UserControl SelectedView
    {
        get
        {
            return _selectedView;
        }
        set
        {
            _selectedView = value;
        }
    }

    private static QueuePanel CurrentQueuePanel { get; set; }
    private static MergePanel CurrentMergePanel { get; set; }



    private void OnPanelButtonClickHandler(object sender, RoutedEventArgs e)
    {
        switch (((Button)sender).Tag)
        {
            case "Queue":
                SelectedView = CurrentQueuePanel;
                break;
            case "Merge":
                SelectedView = CurrentMergePanel;
                break;
            default:
                ((Button)sender).Content = "Somethin went wrong...";
                break;

        }
        e.Handled = true;
    }
}

And in the .axaml

  <Button Tag="Queue" Click="{Binding OnPanelButtonClickHandler}" ClickMode="Press" Margin="0" Grid.Row="0" Grid.Column="0" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" Content="Queue" Classes="btn" />

The button event will not work in any fashion I have tried. In this attempt It gives me the exception

'Unable to find suitable setter or adder for property Click of type Avalonia.Controls:Avalonia.Controls.Button for argument Avalonia.Markup:Avalonia.Data.Binding, available setter parameter lists are: System.EventHandler`1[[Avalonia.Interactivity.RoutedEventArgs, Avalonia.Interactivity, Version=0.10.12.0, Culture=neutral, PublicKeyToken=c8d484a7012f9a8b]] Line 40, position 26.' Line number '40' and line position '26'.

If I use a Command instead of Click, it will compile however the button becomes disabled.

Answer 1

You are getting this exception because Click is the RoutedEvent and OnPanelButtonClickHandler should be in the *.axaml.cs code behind.

If you want to call the function in your view model from the view you should use Command property and bind to the function or implement a command in your view model.

In your case the button is inactive when you bind to the command because you do not pass the required parameters. This should work:

private void OnPanelButtonClickHandler(string parameter)

<Button Command="{Binding OnPanelButtonClickHandler}" CommandParameter="Queue" .../>

You can find more information in the docs