WPF Two-dimensional DataGrid/ListView?

Question

I have a table Item that consists of 3 columns:

ItemId int PK
RoomId int FK
UnitId int FK
Cost money

I want to have a DataGri

Answer 1

Firstly, you'd need to convert your collection of Item objects into a suitable collection:

var dict = data.Select(i => i.UnitId).Distinct()
    .ToDictionary(u =>  u, u => data
        .Where(i => i.UnitId == u)
        .ToDictionary(d => d.RoomId, d => d));
var rooms = dict.Values.First().Keys;
DataContext = Tuple.Create(dict, rooms);

and then you need an ItemsControl with the correct DataTemplate configuration

<Grid>
  <Grid.RowDefinitions>
    <RowDefinition Height="Auto" />
    <RowDefinition Height="Auto" />
  </Grid.RowDefinitions>
  <ItemsControl ItemsSource="{Binding Item2}">
    <ItemsControl.ItemsPanel>
      <ItemsPanelTemplate>
        <StackPanel Orientation="Horizontal"
                    Margin="80,0,0,0" />
      </ItemsPanelTemplate>
    </ItemsControl.ItemsPanel>
    <ItemsControl.ItemTemplate>
      <DataTemplate>
        <TextBlock HorizontalAlignment="Center"
                   Foreground="Blue"
                   Width="80"
                   Margin="5">
                        <Run Text="Room" />
                        <Run Text="{Binding Mode=OneWay}" />
        </TextBlock>
      </DataTemplate>
    </ItemsControl.ItemTemplate>
  </ItemsControl>
  <ItemsControl ItemsSource="{Binding Item1}"
                AlternationCount="{Binding Count}"
                Grid.Row="1">
    <ItemsControl.ItemTemplate>
      <DataTemplate>
        <StackPanel Orientation="Horizontal">
          <TextBlock VerticalAlignment="Center"
                     Foreground="Blue"
                     Width="80">
                        <Run Text="Unit" />
                        <Run Text="{Binding Key, Mode=OneWay}" />
          </TextBlock>
          <ItemsControl ItemsSource="{Binding Value}"
                        VerticalAlignment="Center">
            <ItemsControl.ItemsPanel>
              <ItemsPanelTemplate>
                <StackPanel Orientation="Horizontal" />
              </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
            <ItemsControl.ItemTemplate>
              <DataTemplate>
                <TextBlock Text="{Binding Path=Value.Cost, StringFormat={}{0:C}}"
                           Margin="5"
                           Width="80" />
              </DataTemplate>
            </ItemsControl.ItemTemplate>
          </ItemsControl>
        </StackPanel>
      </DataTemplate>
    </ItemsControl.ItemTemplate>
  </ItemsControl>
</Grid>

and then you get this: