MainWindow.xaml

<Window x:Class="BulkQuery.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"
        xmlns:local="clr-namespace:BulkQuery"
        xmlns:properties="clr-namespace:BulkQuery.Properties"
        mc:Ignorable="d"
        Title="Bulk Query" Height="500" Width="800" Loaded="Window_Loaded" Closing="Window_Closing" KeyDown="Window_KeyDown">

    <Window.Resources>
        <ResourceDictionary>
            <Style x:Key="TreeViewItemStyle" TargetType="TreeViewItem">
                <Setter Property="IsExpanded" Value="{Binding IsExpanded}" />
                <Setter Property="KeyboardNavigation.AcceptsReturn" Value="True" />
                <EventSetter Event="PreviewMouseRightButtonDown" Handler="DatabasesTreeView_PreviewMouseButton" />
            </Style>

            <HierarchicalDataTemplate x:Key="CheckBoxItemTemplate" ItemsSource="{Binding Children, Mode=OneTime}">
                <StackPanel Orientation="Horizontal">
                    <CheckBox Focusable="False" IsChecked="{Binding IsChecked}" VerticalAlignment="Center" />
                    <ContentPresenter x:Name="Content" Content="{Binding Name, Mode=OneTime}" Margin="2,0" />
                </StackPanel>
            </HierarchicalDataTemplate>
        </ResourceDictionary>
    </Window.Resources>

    <DockPanel>
        <Menu DockPanel.Dock="Top">
            <MenuItem Header="_File">
                <MenuItem Header="_Add Server..." Click="MenuItem_AddServer_OnClick"  />
                <MenuItem Header="_Hide System Databases" Name="MenuItemHideSystemDatabases" IsCheckable="True" IsChecked="{Binding Path=Settings.HideSystemDatabases, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" />
                <MenuItem Focusable="False">
                    <MenuItem.Header>
                        <Grid>
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="Auto" />
                                <ColumnDefinition Width="40" />
                            </Grid.ColumnDefinitions>
                            <Label Content="Sql Command Timeout (seconds):" Margin="0,3,6,0" Padding="0" />
                            <TextBox Margin="0,3,0,3" Grid.Column="1" PreviewTextInput="ValidateTextboxEntryIsInteger" Text="{Binding Path=Settings.SqlTimeout, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Window}}" />
                        </Grid>
                    </MenuItem.Header>
                </MenuItem>
                <MenuItem Header="_Exit" />
            </MenuItem>
            <MenuItem Header="_Help">
                <MenuItem Header="_Open User Settings" Click="MenuItem_OpenUserSettings_Click" Name="OpenUserSettingsMenuItem" />
                <MenuItem Header="_View On Github" Click="MenuItem_Github_Click" Name="ViewOnGithubMenuItem" />
            </MenuItem>
        </Menu>

        <Grid Name="MainGrid">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="250" />
                <ColumnDefinition Width="5" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>
            <TreeView Grid.Column="0" x:Name="DatabasesTreeView"
                          ItemContainerStyle="{StaticResource TreeViewItemStyle}"
                          ItemTemplate="{StaticResource CheckBoxItemTemplate}" />
            <GridSplitter Grid.Column="1" Width="5" HorizontalAlignment="Stretch" DragDelta="MainGrid_OnDragDelta" />
            <Grid Grid.Column="2" Name="RightHandGrid">
                <Grid.RowDefinitions>
                    <RowDefinition Height="250" />
                    <RowDefinition Height="5" />
                    <RowDefinition Height="*" />
                </Grid.RowDefinitions>
                <DockPanel Grid.Row="0">
                    <StackPanel Margin="5" Orientation="Horizontal" DockPanel.Dock="Bottom">
                        <Button Name="RunQueryButton" Click="ButtonQuery_OnClick" Padding="10 2">Run Query (F5)</Button>
                    </StackPanel>
                    <avalonEdit:TextEditor
                        xmlns:avalonEdit="http://icsharpcode.net/sharpdevelop/avalonedit"
                        Name="QueryTextBox"
                        SyntaxHighlighting="TSQL"
                        FontFamily="Courier New"
                        FontSize="10pt"
                        ShowLineNumbers="True" 
                        HorizontalScrollBarVisibility="Auto"
                        VerticalScrollBarVisibility="Auto"
                        LineNumbersForeground="#FF2B91AF"/>
                </DockPanel>
                <GridSplitter Grid.Row="1" Height="5" HorizontalAlignment="Stretch" DragDelta="RightHandGrid_OnDragDelta" />
                <DockPanel Grid.Row="2">
                    <Grid Grid.Column="2" Name="ResultsGrid">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="0" Name="TextBoxMessagesRow" />
                            <RowDefinition Height="5" />
                            <RowDefinition Height="*" />
                        </Grid.RowDefinitions>
                        <TextBox x:Name="TextBoxMessages" IsReadOnly="True" VerticalScrollBarVisibility="Auto" Foreground="Red" Grid.Row="0" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
                        <GridSplitter Grid.Row="1" Height="5" HorizontalAlignment="Stretch" />
                        <DataGrid x:Name="ResultDataGrid" IsReadOnly="True" SelectionUnit="CellOrRowHeader" AreRowDetailsFrozen="True" Grid.Row="2" />
                    </Grid>
                </DockPanel>
            </Grid>
        </Grid>
    </DockPanel>
</Window>