How to hide wpf datagrid columns depending on a property

Question

I have the following WPF sample program:

Xaml:

Answer 1

Solution proposed by H.B. is really good and has true WPF MVVM spirit. Use it where possible.

In my particular case something went wrong so I came out with different way, as my project is not strict MVVM, so I can use coded solution.

In CustomView.xaml name assigned to column:

<DataGrid>
    <DataGrid.Columns>
        <DataGridTemplateColumn x:Name="MachinesColumn" ... />
        ...

In CustomView.xaml.cs we have a simple property which directly changes visibility of column:

public Visibility MachinesColumnVisible
{
    get { return MachinesColumn.Visibility; }
    set
    {
        if (value == MachinesColumn.Visibility)
            return;
        MachinesColumn.Visibility = value;
    }
}

Answer 2

Visibility on DataGridTextColumn is not a DependencyProperty and can't be databound. Use a DataGridTemplateColumn and bind the visibility of the controls within the template.

Edit: Actually, this statement only applies to silverlight. See this other SO question for further details.

How to bind DataGridColumn.Visibility?

I asked about the easiest way to tell whether a property is a dependency here.

How can I most easily determine whether a property is a dependency property?

Answer 3

A column in a datagrid is an abstract object which does not appear in the visual tree, thus you cannot use RelativeSource-binding, ElementName will not work either since it will not find a governing FrameworkContentElement so you are in kind of a bind.

One way that works is via Source and x:Reference, for that you will need to name your window and move the column to its resources to avoid a cyclical dependency error:

<Window Name="_window" ...>
    <Window.Resources>
        <DataGridTextColumn x:Key="ThatPeskyColumn"
                            Binding="{Binding Size}"
                            Visibility="{Binding DataContext.Flag, Source={x:Reference _window}, Converter={StaticResource BoolToVis}}"/>
    </Window.Resources>
    <!-- ... -->
        <DataGrid AutoGenerateColumns="False" Name="Blumen" 
                  ItemsSource="{Binding Leaves}">
            <DataGrid.Columns>
                <StaticResource ResourceKey="ThatPeskyColumn"/>
                <!-- ... -->

Great fun.

Answer 4

I would prefer a more elegant approach which involves using a Freezable.

<Window.Resources>

    <DiscreteObjectKeyFrame x:Key="FlagKey" Value="{Binding Flag}"/>

</Window.Resources>


<DataGridTextColumn ... Visibility="{Binding Value, Source={StaticResource FlagKey}, ...}" />