MVVM and Databinding with UniformGrid

Question

I'm trying to style the back of a WPF chart with some rectangles. I'm using MVVM, and I need the rectangles to be uniformly sized. When defined via Xaml, this works with a fixed "BucketCount" of 4:

<VisualBrush>
  <VisualBrush.Visual>
  <UniformGrid Height="500" Width="500" Rows="1" Columns="{Binding BucketCount}">
    <Rectangle Grid.Row="0" Grid.Column="0" Fill="#22ADD8E6" />
    <Rectangle Grid.Row="0" Grid.Column="1" Fill="#22D3D3D3"/>
    <Rectangle Grid.Row="0" Grid.Column="2" Fill="#22ADD8E6"/>
    <Rectangle Grid.Row="0" Grid.Column="3" Fill="#22D3D3D3"/>
  </UniformGrid>        
 </VisualBrush.Visual>
<VisualBrush>

How can I bind my ObservableCollection of Rectangles? There is no "ItemsSource" property on UniformGrid. Do I need to use an ItemsControl? If so, how can I do this?

Thanks in advance.

Answer 1

You could use ItemsControl to Bind like this. Simple example where ItemsSource is just an ObservableCollection<Brush>

<VisualBrush>
    <VisualBrush.Visual>
        <ItemsControl x:Name="itemsControl" ItemsSource="{Binding MyBrushes}">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <UniformGrid Height="500" Width="500" Rows="1"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Rectangle Fill="{Binding}"/>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
        </ItemsControl>
    </VisualBrush.Visual>
</VisualBrush>

Update
It works for my usage scenario, but I might be missing something here. Here's the full code I've tried. I get the same result from both

MainWindow.xaml

<Grid>
    <Grid.Background>
        <VisualBrush>
            <VisualBrush.Visual>
                <ItemsControl x:Name="itemsControl" ItemsSource="{Binding MyBrushes}">
                    <ItemsControl.ItemsPanel>
                        <ItemsPanelTemplate>
                            <UniformGrid Height="500" Width="500" Rows="1"/>
                        </ItemsPanelTemplate>
                    </ItemsControl.ItemsPanel>
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <Rectangle Fill="{Binding}"/>
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
                <!--<UniformGrid Height="500" Width="500" Rows="1" Columns="4">
                    <Rectangle Grid.Row="0" Grid.Column="0" Fill="#22ADD8E6" />
                    <Rectangle Grid.Row="0" Grid.Column="1" Fill="#22D3D3D3"/>
                    <Rectangle Grid.Row="0" Grid.Column="2" Fill="#22ADD8E6"/>
                    <Rectangle Grid.Row="0" Grid.Column="3" Fill="#22D3D3D3"/>
                </UniformGrid>-->
            </VisualBrush.Visual>
        </VisualBrush>
    </Grid.Background>
</Grid>

MainWindow.xaml.cs

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        BrushConverter brushConverter = new BrushConverter();
        MyBrushes = new ObservableCollection<Brush>();
        MyBrushes.Add(brushConverter.ConvertFrom("#22ADD8E6") as Brush);
        MyBrushes.Add(brushConverter.ConvertFrom("#22D3D3D3") as Brush);
        MyBrushes.Add(brushConverter.ConvertFrom("#22ADD8E6") as Brush);
        MyBrushes.Add(brushConverter.ConvertFrom("#22D3D3D3") as Brush);
        this.DataContext = this;
    }

    public ObservableCollection<Brush> MyBrushes
    {
        get;
        set;
    }
}