<Window x:Class="WPF_4_DockPanel.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>
        <DockPanel LastChildFill="False">
            <Button Width="100" Height="40" DockPanel.Dock="Left" />
            <Button Width="100" Height="40" DockPanel.Dock="Top" />
            <Button Width="100" Height="40" DockPanel.Dock="Right" />
            <Button Width="100" Height="40" DockPanel.Dock="Bottom" />
        </DockPanel>
    </Grid>
</Window>