Can I bind the visibility of a WPF ComboBox control to the presence/absence of items obtained from a Command?

Question

Can I bind the visibility of a WPF ComboBox control to the presence/absence of items obtained from a Command that populates the ComboBox’s ItemsSource property? In a nutshell, in a situation like:

<ComboBox ItemsSource="{Binding MyCommand.Result, Mode=OneWay}" Visibility="..." />

Can I bind the value of the Visibility property to the presence or absence of items inside MyCommand.Result to hide/show it accordingly?

Answer 1

You could use a Style with a DataTrigger that binds to a source property, e.g.:

<ComboBox ItemsSource="{Binding MyCommand.Result, Mode=OneWay}">
    <ComboBox.Style>
        <Style TargetType="ComboBox">
            <Style.Triggers>
                <DataTrigger Binding="{Binding MyCommand.Result.Count}" Value="0">
                    <Setter Property="Visibility" Value="Collapsed" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </ComboBox.Style>
</ComboBox>

Or you could bind to the HasItems property of the control itself:

<ComboBox ItemsSource="{Binding MyCommand.Result, Mode=OneWay}">
    <ComboBox.Style>
        <Style TargetType="ComboBox">
            <Style.Triggers>
                <Trigger Property="HasItems" Value="False">
                    <Setter Property="Visibility" Value="Collapsed" />
                </Trigger>
            </Style.Triggers>
        </Style>
    </ComboBox.Style>
</ComboBox>