WPF main left height 100%, main right height 100% and footer - wpf

Question

I have created the following design with main left, main right and footer.
However I want main left to be height 100%, so that the dark gray background color goes all the way down to the footer.
I've tried to set height=*, but it doesnt help.
My design:
NewProjectWindow.xaml
<Window x:Class="QuickImageForensicsWPF.NewProject.NewProjectWindow"
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"
xmlns:local="clr-namespace:QuickImageForensicsWPF.NewProject"
mc:Ignorable="d"
Title="New Project | Quick Image Forensics" Height="{DynamicResource {x:Static SystemParameters.MaximizedPrimaryScreenHeightKey}}" Width="{DynamicResource {x:Static SystemParameters.MaximizedPrimaryScreenWidthKey}}" Top="0" Left="0">
<Window.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="..\res\style\Btn.xaml" />
<ResourceDictionary Source="..\res\style\Input.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Window.Resources>
<Grid Background="#FF45474A">
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="Auto" />
</Grid.RowDefinitions>
<!-- Main -->
<StackPanel x:Name="stackPanelMain" Grid.Row="0" Grid.Column="0" >
<Grid Background="#FF45474A">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="400" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<StackPanel x:Name="stackPanelLeft" Grid.Row="0" Grid.Column="0" Background="#FF393939" Margin="0,0,20,0">
<!-- Left content -->
<Label x:Name="labelProjects" Content="New project" Margin="0,20,0,0" FontSize="16" Foreground="#FFBABAA8" FontWeight="Bold"/>
<Label x:Name="labelNewProjectStep01" Content="Project information" Margin="0,0,0,0" FontSize="14" Foreground="#FFBABAA8" FontStyle="Italic" />
<Label x:Name="labelNewProjectStep02" Content="Automated tasks" Margin="0,0,0,0" FontSize="14" Foreground="#FFBABAA8" />
<Label x:Name="labelNewProjectStep03" Content="Search" Margin="0,0,0,0" FontSize="14" Foreground="#FFBABAA8" />
<!-- //Left content -->
</StackPanel>
<StackPanel x:Name="stackPanelRight" Grid.Row="0" Grid.Column="1">
<!-- Right content -->
<DockPanel x:Name="dockPanelMain" LastChildFill="False">
<local:NewProjectStep01ProjectInformationUserControl x:Name="newProjectStep01ProjectInformationUserControl" Panel.ZIndex="0" />
<local:NewProjectStep02AutomatedTasksUserControl x:Name="NewProjectStep02AutomatedTasksUserControl" Panel.ZIndex="1" />
<local:NewProjectStep03SearchUserControl x:Name="NewProjectStep03SearchUserControl" Panel.ZIndex="2" />
</DockPanel>
<!-- //Right content -->
</StackPanel>
</Grid>
</StackPanel>
<!-- //Main -->
<!-- Footer -->
<StackPanel x:Name="stackPanelFooter" Grid.Row="1" Grid.Column="0">
<Border BorderBrush="#FF323232" BorderThickness="1" DockPanel.Dock="Top" Padding="0,0,0,0">
<Grid Background="#FF45474A">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="400" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<StackPanel Grid.Column="1" Orientation="Horizontal" Margin="0,20,0,20">
<Button x:Name="buttonPrevious" Content=" Previous " VerticalAlignment="Bottom" Click="buttonPrevious_Click" Style="{StaticResource btn_default}" HorizontalAlignment="Left" Margin="0,0,10,0" />
<Button x:Name="buttonNext" Content=" Next " VerticalAlignment="Bottom" Click="buttonNext_Click" Style="{StaticResource btn_default_success}" HorizontalAlignment="Left" />
</StackPanel>
</Grid>
</Border>
</StackPanel>
<!-- //Footer -->
</Grid>
</Window>
The program is C# WPF with .NETFramework v4.7.2.

Answer 1

For Main, I replaced stackpanel with Grid layout and added VerticalAlignment="Stretch".
<Grid x:Name="stackPanelMain" Grid.Row="0" Grid.Column="0" VerticalAlignment="Stretch" >
<Grid Background="#FF45474A" VerticalAlignment="Stretch" >
<Grid.RowDefinitions>
<RowDefinition Height="400*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="400" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<StackPanel x:Name="stackPanelLeft" Grid.Row="0" Grid.Column="0" Background="#FF393939" Margin="0,0,20,0">
<!-- Left content -->
<Label x:Name="labelProjects" Content="New project" Margin="0,20,0,0" FontSize="16" Foreground="#FFBABAA8" FontWeight="Bold"/>
<Label x:Name="labelNewProjectStep01" Content="Project information" Margin="0,0,0,0" FontSize="14" Foreground="#FFBABAA8" FontStyle="Italic" />
<Label x:Name="labelNewProjectStep02" Content="Automated tasks" Margin="0,0,0,0" FontSize="14" Foreground="#FFBABAA8" />
<Label x:Name="labelNewProjectStep03" Content="Search" Margin="0,0,0,0" FontSize="14" Foreground="#FFBABAA8" />
<!-- //Left content -->
</StackPanel>
<StackPanel x:Name="stackPanelRight" Grid.Row="0" Grid.Column="1">
<!-- Right content -->
<DockPanel x:Name="dockPanelMain" LastChildFill="False">
<!--<local:NewProjectStep01ProjectInformationUserControl x:Name="newProjectStep01ProjectInformationUserControl" Panel.ZIndex="0" />
<local:NewProjectStep02AutomatedTasksUserControl x:Name="NewProjectStep02AutomatedTasksUserControl" Panel.ZIndex="1" />
<local:NewProjectStep03SearchUserControl x:Name="NewProjectStep03SearchUserControl" Panel.ZIndex="2" />-->
</DockPanel>
<!-- //Right content -->
</StackPanel>
</Grid>
</Grid>