<Window x:Class="Layout.GridDemo"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Grid Demo"
    >
  <Grid>
    <Grid.RowDefinitions>
      <RowDefinition />
      <RowDefinition />
      <RowDefinition />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
      <ColumnDefinition />
      <ColumnDefinition />
      <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <Button Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2">A</Button>
    <Button Grid.Row="0" Grid.Column="2">C</Button>
    <Button Grid.Row="1" Grid.Column="0" Grid.RowSpan="2">D</Button>
    <Button Grid.Row="1" Grid.Column="1">E</Button>
    <Button Grid.Row="1" Grid.Column="2">F</Button>
    <Button Grid.Row="2" Grid.Column="1">H</Button>
    <Button Grid.Row="2" Grid.Column="2">I</Button>
  </Grid>
</Window>
