Bind ICommand in Converter

Question

In my view I'm using an ItemsControl to display several Buttons. The XAML for the ItemsControl is:

<ItemsControl ItemsSource="{Binding CustomDirectories, UpdateSourceTrigger=PropertyChanged, Converter={StaticResource buttonConverter}}" Margin="2">
    <ItemsControl.ItemsPanel>
        <ItemsPanelTemplate>
            <WrapPanel Orientation="Vertical"/>
        </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
</ItemsControl>

In the ViewModel of my View I have an ICommand which can handle the Button-Click. I need the Command here, because I also need some other Properties here.

The Converter for creating the buttons is:

public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
    if (value is ObservableCollection<DVDDirectory>)
    {
        ObservableCollection<CustomDirectory> customDirectories = (ObservableCollection<CustomDirectory>)value;
        List<Button> buttons = new List<Button>();

        foreach (CustomDirectory customDirectory in customDirectories)
        {
            Button button = new Button
            {
                Margin = new Thickness(2),
                Width = 140,
                Height = 25,
                Content = Path.GetFileName(customDirectory.Path)
            };
            buttons.Add(button);
        }
        return buttons;
    }
    return value;
}

My question now is: How can I assign the command from the ViewModel to the Command in the Converter where the Buttons are created?

I tried to pass the DataContext of my View to the Converter as ConverterParameter, but there I get an BindingException.

converters are not for this purpose – D J Jan 27 '14 at 10:11 — D J, Jan 27 '14 at 10:11

Gerrit Fölster · Answer 1 · 2014-01-27T09:21:03.827

1

You can access the DataContext of your View via ElementName Binding:

<ItemsControl Name="MyItemsControl">
    <ItemsControl.ItemTemplate>
        <DataTemplate>                    
            <Button Command="{Binding ElementName=MyItemsControl, Path=DataContext.MyCommand}" CommandParameter="{Binding}"></Button>                    
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

The ConverterParameter must be a string and can not be databound.

edited Jan 27 '14 at 09:21

answered Jan 27 '14 at 09:01

Gerrit Fölster

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This solution is working if I just have one single button. But in my case the buttons are created at runtime – Tomtom Jan 27 '14 at 09:07
Good to hear, maybe you want to edit your original post and share your solution. – Gerrit Fölster Jan 27 '14 at 09:23

score 0 · Accepted Answer · answered Jan 27 '14 at 09:21

0

I solved it by my own.

I just created a singelton-class where the Command of the ViewModel is passed in the constructor. At the moment the converter is called, the singelton already has the Command and the Converter can assign the command.

answered Jan 27 '14 at 09:21

Tomtom

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But actually you should use data template for this. The datatemplate should have a button binded with the viewmodel.command. – D J Jan 27 '14 at 10:13

Bind ICommand in Converter

2 Answers2