<Window x:Class="WPF_15_GridSplitter.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="50" />
            <RowDefinition MinHeight="100"/>
            <RowDefinition Height="5" />
            <RowDefinition Height="50" MinHeight="30" />
        </Grid.RowDefinitions>

        <!-- <Grid.ColumnDefinitions> -->
        <!--     <ColumnDefinition /> -->
        <!--     <ColumnDefinition /> -->
        <!--     <ColumnDefinition /> -->
        <!-- </Grid.ColumnDefinitions> -->

        <Rectangle Grid.Row="0" Fill="Red" />

        <Grid Grid.Row="1">
            <Grid.ColumnDefinitions>
                <ColumnDefinition MinWidth="100" />
                <ColumnDefinition Width="5" />
                <ColumnDefinition />
                <ColumnDefinition Width="5" />
                <ColumnDefinition />
            </Grid.ColumnDefinitions>
            <Rectangle Grid.Column="0" Fill="Yellow" />

            <GridSplitter Grid.Column="1" HorizontalAlignment="Stretch" ResizeDirection="Columns" ShowsPreview="False" />

            <Rectangle Grid.Column="2" Fill="Green" />

            <GridSplitter Grid.Column="3" HorizontalAlignment="Stretch" ResizeDirection="Columns" ShowsPreview="False" />

            <Rectangle Grid.Column="4" Fill="Orange" />
        </Grid>

        <GridSplitter Grid.Row="2 " HorizontalAlignment="Stretch" ResizeDirection="Rows"
                      Background="White" ShowsPreview="False" />

        <Rectangle Grid.Row="3" Fill="Blue" />
    </Grid>
</Window>