Develop Reference

WPF : How to change the MouseOver/Selected background colour of a GridView row

I'm having a hard time finding a solution to this so would appreciate any help.
I need to be able to change the background of a GridView row when the mouse is over or of if the row is selected.
Here's my ListView Style.
<Style x:Key="{x:Static GridView.GridViewScrollViewerStyleKey}"
TargetType="ScrollViewer">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ScrollViewer">
<Grid Background="{TemplateBinding Background}">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<DockPanel Margin="{TemplateBinding Padding}">
<ScrollViewer DockPanel.Dock="Top"
HorizontalScrollBarVisibility="Hidden"
VerticalScrollBarVisibility="Hidden"
Focusable="false">
<GridViewHeaderRowPresenter Margin="2,0,2,0"
Columns="{Binding Path=TemplatedParent.View.Columns,
RelativeSource={RelativeSource TemplatedParent}}"
ColumnHeaderContainerStyle="{Binding
Path=TemplatedParent.View.ColumnHeaderContainerStyle,
RelativeSource={RelativeSource TemplatedParent}}"
ColumnHeaderTemplate="{Binding
Path=TemplatedParent.View.ColumnHeaderTemplate,
RelativeSource={RelativeSource TemplatedParent}}"
ColumnHeaderTemplateSelector="{Binding
Path=TemplatedParent.View.ColumnHeaderTemplateSelector,
RelativeSource={RelativeSource TemplatedParent}}"
AllowsColumnReorder="{Binding
Path=TemplatedParent.View.AllowsColumnReorder,
RelativeSource={RelativeSource TemplatedParent}}"
ColumnHeaderContextMenu="{Binding
Path=TemplatedParent.View.ColumnHeaderContextMenu,
RelativeSource={RelativeSource TemplatedParent}}"
ColumnHeaderToolTip="{Binding
Path=TemplatedParent.View.ColumnHeaderToolTip,
RelativeSource={RelativeSource TemplatedParent}}"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</ScrollViewer>
<ScrollContentPresenter Name="PART_ScrollContentPresenter"
KeyboardNavigation.DirectionalNavigation="Local"/>
</DockPanel>
<ScrollBar Name="PART_HorizontalScrollBar"
Orientation="Horizontal"
Grid.Row="1"
Maximum="{TemplateBinding ScrollableWidth}"
ViewportSize="{TemplateBinding ViewportWidth}"
Value="{TemplateBinding HorizontalOffset}"
Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}"/>
<ScrollBar Name="PART_VerticalScrollBar"
Grid.Column="1"
Maximum="{TemplateBinding ScrollableHeight}"
ViewportSize="{TemplateBinding ViewportHeight}"
Value="{TemplateBinding VerticalOffset}"
Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="GridViewColumnHeaderGripper" TargetType="Thumb">
<Setter Property="Width" Value="18"/>
<Setter Property="Background" Value="{StaticResource NormalBorderBrush}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Thumb}">
<Border Padding="{TemplateBinding Padding}"
Background="Transparent">
<Rectangle HorizontalAlignment="Center"
Width="1"
Fill="{TemplateBinding Background}"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="{x:Type GridViewColumnHeader}"
TargetType="GridViewColumnHeader">
<Setter Property="HorizontalContentAlignment" Value="Center"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="GridViewColumnHeader">
<Grid>
<Border Name="HeaderBorder"
BorderThickness="0,1,0,1"
BorderBrush="{StaticResource NormalBorderBrush}"
Background="{StaticResource ControlDarkBrush}"
Padding="2,0,2,0">
<ContentPresenter Name="HeaderContent"
Margin="0,0,0,1"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
RecognizesAccessKey="True"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
<Thumb x:Name="PART_HeaderGripper"
HorizontalAlignment="Right"
Margin="0,0,-9,0"
Style="{StaticResource GridViewColumnHeaderGripper}"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="true">
<Setter TargetName="HeaderBorder"
Property="Background" Value="{StaticResource NormalBrush}"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter TargetName="HeaderBorder"
Property="Background" Value="{StaticResource PressedBrush}"/>
<Setter TargetName="HeaderContent"
Property="Margin" Value="1,1,0,0"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground"
Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="Role" Value="Floating">
<Setter Property="Opacity" Value="0.7"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="GridViewColumnHeader">
<Canvas Name="PART_FloatingHeaderCanvas">
<Rectangle Fill="#60000000"
Width="{TemplateBinding ActualWidth}"
Height="{TemplateBinding ActualHeight}"/>
</Canvas>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
<Trigger Property="Role" Value="Padding">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="GridViewColumnHeader">
<Border Name="HeaderBorder"
BorderThickness="0,1,0,1"
BorderBrush="{StaticResource NormalBorderBrush}"
Background="{StaticResource ControlDarkBrush}"/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
<Style x:Key="StyleListView" TargetType="ListView">
<Setter Property="SnapsToDevicePixels" Value="true"/>
<Setter Property="OverridesDefaultStyle" Value="true"/>
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto"/>
<Setter Property="ScrollViewer.CanContentScroll" Value="true"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ListView">
<Border Name="Border"
BorderThickness="1"
BorderBrush="{StaticResource BorderLightBrush}"
Background="{StaticResource ControlDarkBrush}">
<ScrollViewer Style="{DynamicResource
{x:Static GridView.GridViewScrollViewerStyleKey}}">
<ItemsPresenter />
</ScrollViewer>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsGrouping"
Value="true">
<Setter Property="ScrollViewer.CanContentScroll"
Value="false"/>
</Trigger>
<Trigger Property="IsEnabled"
Value="false">
<Setter TargetName="Border"
Property="Background"
Value="{StaticResource DisabledBorderDarkBrush}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The closest I've come to getting to an answer is this post (code is omitted from my Style as it didn't have any effect) :-
Change ListViewItem background colour on mouse over
However, I'm still unable to control the mouseover and selected colours. I'm getting closer as the post above suggests that it is a button which is actually doing the highlighting and selecting but I don't know how to incorporate that in to my existing style.
Here's the current effect of the Style. The top row is selected, the third row is mouse-overed, the other two rows are normal.
Mouseover / selected colours
BTW, the Style I'm using was extracted from Blend and I tweaked it to use my app colours.
I don't think my Class code would be relevant here but correct me if I'm wrong and I will post it.

I think you need to add a style for the ListViewItems and set the ListView.ItemContainerStyle:
<!-- New style -->
<Style x:Key="StyleListViewItem" TargetType="ListViewItem">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Green"/>
</Trigger>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Background" Value="Blue"/>
</Trigger>
</Style.Triggers>
</Style>
<!-- Existing style -->
<Style x:Key="StyleListView" TargetType="ListView">
<Setter Property="ItemContainerStyle" Value="{StaticResource StyleListViewItem}"/>
<Setter Property="SnapsToDevicePixels" Value="true"/>
<!-- ... -->
</Style>

How do I move the AvalonDock Anchorable Pane tab to the top instead of the bottom?

I am using AvalonDock in a project and would like to use the Anchorable Pane, but instead of the tab appearing at the bottom, I would like it to appear at the top like it does on a Document Pane. For my project, a Document Pane is not the appropriate control, so I need to find a way to make the Anchorable Pane appear in the same way.

According to Issue Ticket found on CodePlex there is a bug that prevents changing the TabStripPlacement to the top. The way to achieve this is to replace the existing style with one like this:
<Style x:Key="MyCustomAnchorablePaneControlStyle" TargetType="{x:Type xcad:LayoutAnchorablePaneControl}">
<Setter Property="TabStripPlacement" Value="Top"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type xcad:LayoutAnchorablePaneControl}">
<Grid ClipToBounds="true" SnapsToDevicePixels="true" KeyboardNavigation.TabNavigation="Local">
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<!--Following border is required to catch mouse events-->
<Border Background="Transparent" Grid.RowSpan="2"/>
<xcad:AnchorablePaneTabPanel x:Name="HeaderPanel" Margin="2,0,2,2" IsItemsHost="true" Grid.Row="0" KeyboardNavigation.TabIndex="1" Panel.ZIndex="1"/>
<Border x:Name="ContentPanel" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.Column="0" KeyboardNavigation.DirectionalNavigation="Contained" Grid.Row="1" KeyboardNavigation.TabIndex="2" KeyboardNavigation.TabNavigation="Cycle">
<ContentPresenter x:Name="PART_SelectedContentHost" ContentSource="SelectedContent" Margin="{TemplateBinding Padding}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="ItemContainerStyle">
<Setter.Value>
<Style TargetType="{x:Type TabItem}">
<Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay}"/>
<Setter Property="ToolTip" Value="{Binding ToolTip}"/>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type TabControl}}, Path=Items.Count}" Value="1">
<Setter Property="Visibility" Value="Collapsed"/>
</DataTrigger>
</Style.Triggers>
</Style>
</Setter.Value>
</Setter>
<Setter Property="ItemTemplate">
<Setter.Value>
<DataTemplate>
<xcad:LayoutAnchorableTabItem Model="{Binding}"/>
</DataTemplate>
</Setter.Value>
</Setter>
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<xcad:LayoutAnchorableControl Model="{Binding}"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>

Bug in WPF user control

I created a user control with a menu in WPF. It was working just fine and now I'm seeing a format issue with the MenuItem.Header. Basically if I add a header where the name has a "_" character it deletes it. For instance, if I add this to the header: "Test_Header_Name," it shows as: "TestHeader_Name." So basically it formats/manipulates the string and deletes the first "_" character. I know things don't just happened out of the blue. I am sure, I must have done something at some point to change the format... but I cannot figure out what it was.
Here is the C# to test the menu:
public partial class MenuControl : UserControl
{
public MenuControl()
{
InitializeComponent();
MenuItem main = new MenuItem();
main.Header = "Sum(Test_Header_Name)";
for (int i = 0; i < 10; i++)
{
main.Items.Add("Test_" + i);
}
main.Items.Add(new Separator());
main.Items.Add("Remove");
this.PrincipalMenu.Items.Add(main);
}
}
And this is the XAML (which is where I think it is happening):
<UserControl x:Class="WindowsFormsApplication1.MenuControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="41" d:DesignWidth="380">
<UserControl.Resources>
<!--**************************
* STYLE: MenuItem
************************** -->
<SolidColorBrush x:Key="HighlightedBackgroundBrush" Color="#FFDEDEDE" />
<SolidColorBrush x:Key="MenuBackgroundBrush" Color="White" />
<SolidColorBrush x:Key="NormalBorderBrush" Color="#FFE5DFDF" />
<SolidColorBrush x:Key="SolidMenuFontBrush" Color="Black" />
<SolidColorBrush x:Key="HighlightedText" Color="White" />
<SolidColorBrush x:Key="menuItemBrush" Color="#FFB7B7B7" />
<SolidColorBrush x:Key="WindowBackgroundBrush" Color="#FFF" />
<SolidColorBrush x:Key="SolidBorderBrush" Color="#888" />
<Style x:Key="{x:Type Menu}" TargetType="{x:Type Menu}">
<Setter Property="OverridesDefaultStyle" Value="True"/>
<Setter Property="SnapsToDevicePixels" Value="True"/>
<Setter Property="Height" Value="25"/>
<Setter Property="Foreground" Value="{StaticResource SolidMenuFontBrush}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Menu}">
<Border
Background="{StaticResource MenuBackgroundBrush}"
BorderBrush="{StaticResource MenuBackgroundBrush}"
BorderThickness="1">
<StackPanel ClipToBounds="True" Orientation="Horizontal" IsItemsHost="True"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="{x:Type MenuItem}" TargetType="{x:Type MenuItem}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type MenuItem}">
<Border x:Name="Border" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="0">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition x:Name="Col0" MinWidth="17" Width="Auto" SharedSizeGroup="MenuItemIconColumnGroup"/>
<ColumnDefinition Width="Auto" SharedSizeGroup="MenuTextColumnGroup"/>
<ColumnDefinition Width="Auto" SharedSizeGroup="MenuItemIGTColumnGroup"/>
<ColumnDefinition x:Name="Col3" Width="14"/>
</Grid.ColumnDefinitions>
<!-- ContentPresenter to show an Icon if needed -->
<ContentPresenter Grid.Column="0" Margin="4,0,6,0" x:Name="Icon" VerticalAlignment="Center" ContentSource="Icon"/>
<!-- Glyph is a checkmark if needed for a checkable menu -->
<Grid Grid.Column="0" Visibility="Hidden" Margin="4,0,6,0" x:Name="GlyphPanel" VerticalAlignment="Center">
<Path x:Name="GlyphPanelpath" VerticalAlignment="Center" Fill="{TemplateBinding Foreground}" Data="M0,2 L0,4.8 L2.5,7.4 L7.1,2.8 L7.1,0 L2.5,4.6 z" FlowDirection="LeftToRight"/>
</Grid>
<!-- Content for the menu text etc -->
<ContentPresenter Grid.Column="1" Margin="{TemplateBinding Padding}" x:Name="HeaderHost" RecognizesAccessKey="True" ContentSource="Header"/>
<!-- Content for the menu IGT -->
<ContentPresenter Grid.Column="2" Margin="8,1,8,1" x:Name="IGTHost" ContentSource="InputGestureText" VerticalAlignment="Center"/>
<!-- Arrow drawn path which points to the next level of the menu -->
<Grid Grid.Column="3" Margin="4,0,6,0" x:Name="ArrowPanel" VerticalAlignment="Center">
<Path x:Name="ArrowPanelPath" HorizontalAlignment="Right" VerticalAlignment="Center" Fill="{TemplateBinding Foreground}" Data="M0,0 L0,8 L4,4 z"/>
</Grid>
<!--IsOpen="{Binding Path=IsSubmenuOpen, RelativeSource={RelativeSource TemplatedParent}}"
PopupAnimation="{DynamicResource {x:Static SystemParameters.MenuPopupAnimationKey}}"
-->
<!-- The Popup is the body of the menu which expands down or across depending on the level of the item -->
<Popup Placement="Right" IsOpen="{TemplateBinding IsSubmenuOpen}" x:Name="SubMenuPopup" Focusable="false" PopupAnimation="Fade">
<Border x:Name="SubMenuBorder" SnapsToDevicePixels="True" Background="{StaticResource WindowBackgroundBrush}" BorderBrush="{StaticResource SolidBorderBrush}" BorderThickness="1" Padding="2,2,2,2">
<Grid x:Name="SubMenu" Grid.IsSharedSizeScope="True">
<!--StackPanel holds children of the menu. This is set by IsItemsHost=True-->
<StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle"/>
<!--<ScrollViewer CanContentScroll="True">
<StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle" />
</ScrollViewer>-->
</Grid>
</Border>
</Popup>
</Grid>
</Border>
<!-- These triggers re-configure the four arrangements of MenuItem to show different levels of menu via Role -->
<ControlTemplate.Triggers>
<!-- Role = TopLevelHeader : this is the root menu item in a menu; the Popup expands down
2/6/2013 Luis Garcia
-->
<!--<Trigger Property="Role" Value="TopLevelHeader">
<Setter Property="Padding" Value="6,1,6,1"/>
<Setter Property="Placement" Value="Bottom" TargetName="SubMenuPopup"/>
<Setter Property="MinWidth" Value="0" TargetName="Col0"/>
<Setter Property="Width" Value="Auto" TargetName="Col3"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="GlyphPanel"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="IGTHost"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/>
</Trigger>-->
<!-- Role = TopLevelItem : this is a child menu item from the top level without any child items-->
<Trigger Property="Role" Value="TopLevelItem">
<Setter Property="Padding" Value="6,1,6,1"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/>
</Trigger>
<!-- Role = SubMenuHeader : this is a child menu item which does not have children -->
<Trigger Property="Role" Value="SubmenuHeader">
<Setter Property="DockPanel.Dock" Value="Top"/>
<Setter Property="Padding" Value="0,2,0,2"/>
</Trigger>
<!-- Role = SubMenuItem : this is a child menu item which has children-->
<Trigger Property="Role" Value="SubmenuItem">
<Setter Property="DockPanel.Dock" Value="Top"/>
<Setter Property="Padding" Value="0,2,0,2"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="ArrowPanel"/>
</Trigger>
<Trigger Property="IsSuspendingPopupAnimation" Value="true">
<Setter Property="PopupAnimation" Value="None" TargetName="SubMenuPopup"/>
</Trigger>
<!-- If no Icon is present the we collapse the Icon Content -->
<Trigger Property="Icon" Value="{x:Null}">
<Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/>
</Trigger>
<!-- The GlyphPanel contains the CheckMark -->
<Trigger Property="IsChecked" Value="true">
<Setter Property="Visibility" Value="Visible" TargetName="GlyphPanel"/>
<Setter Property="Visibility" Value="Collapsed" TargetName="Icon"/>
</Trigger>
<!-- Using the system colors for the Menu Highlight and IsEnabled-->
<Trigger Property="IsHighlighted" Value="true">
<Setter Property="Background" Value="{StaticResource HighlightedBackgroundBrush}" TargetName="Border"/>
<Setter Property="Foreground" Value="{StaticResource HighlightedText}"/>
<Setter Property="BorderBrush" Value="{StaticResource NormalBorderBrush}" TargetName="Border"/>
</Trigger>
<Trigger Property="IsHighlighted" Value="false">
<Setter Property="Background" Value="{StaticResource MenuBackgroundBrush}" TargetName="Border"/>
<Setter Property="Foreground" Value="{StaticResource SolidMenuFontBrush}"/>
<Setter Property="BorderBrush" Value="{StaticResource MenuBackgroundBrush}" TargetName="Border"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="LightGray"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>
<UserControl.Foreground>
<SolidColorBrush />
</UserControl.Foreground>
<Grid Height="24" Width="250" HorizontalAlignment="Left">
<Grid.Background>
<SolidColorBrush />
</Grid.Background>
<Menu Name="PrincipalMenu" Margin="0,0,-100,0">
</Menu>
</Grid>
Any help is greatly appreciated!

Underscores are used in WPF Content controls as accelerator keys.
So adding "E_dit" to a content control causes the "d" to be underlined at runtime.
The user can press ALT-D to move focus to the control.
In your case "Test_Header_Name" it's the "H" is prefixed by the underscore, so it is the accelerator key.
The solution is to use two underscores "__" to stop the accelerator key addition.

My guess is that the first underscore is being turned into an AccessKey for the MenuItem since you are using it in the Header. So in the example above, you probably have an AccessKey of 'h' for your MenuItem. See this answer for more on the subject.
I'm not sure if there's a way to override the behavior, perhaps if you use the ascii code for the underscore or something.

How can I shorten a BasedOn style

I'm currently making a "base style" for our application. I started by making a "base style" for our buttons, which will be a nice double-gradient (I created a template with 2 rows, and both rows have a two-point gradient).
So, the base button works fine, now I want to create other buttons based on that style.
This is the code for the base button:
<Style x:Key="BaseButtonStyle" TargetType="{x:Type Button}">
<Setter Property="Height" Value="24"/>
<Setter Property="Width" Value="150" />
<Setter Property="Foreground" Value="{DynamicResource OffWhiteBrush}"/>
<Setter Property="HorizontalContentAlignment" Value="Center"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border x:Name="OuterBorder" BorderBrush="{DynamicResource GrayBorderBrush}" BorderThickness="2" CornerRadius="5">
<Grid x:Name="LayoutGrid">
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Border x:Name="TopBorder" BorderBrush="{x:Null}" BorderThickness="0" CornerRadius="4,4,0,0" Background="{DynamicResource TopGrayGradientBrush}"/>
<Border x:Name="BottomBorder" BorderBrush="{x:Null}" BorderThickness="0" Grid.Row="1" CornerRadius="0,0,4,4" Background="{DynamicResource BottomGrayGradientBrush}"/>
<ContentPresenter x:Name="contentPresenter" Grid.RowSpan="2" HorizontalAlignment="Center" />
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Control.Foreground" TargetName="contentPresenter" Value="{DynamicResource DisabledBrush}"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Margin" TargetName="OuterBorder" Value="1"/>
<Setter Property="Background" TargetName="TopBorder" Value="{DynamicResource TopGrayGradientBrush}"/>
<Setter Property="Background" TargetName="BottomBorder" Value="{DynamicResource BottomGrayGradientBrush}"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" TargetName="TopBorder" Value="{DynamicResource TopBlueGradientBrush}"/>
<Setter Property="Background" TargetName="BottomBorder" Value="{DynamicResource BottomBlueGradientBrush}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
When I create a second button I can do it "BasedOn" the other style:
<Style x:Key="RedButtonStyle" TargetType="{x:Type Button}" BasedOn="{StaticResource BaseButtonStyle}">
...
Inside the grid I've named my gradients: topborder and bottomborder. The problem is that I need to duplicate the code in order to be able to set any code, because the redbuttonStyle doesn't "know" topborder or bottomborder:
<Style x:Key="RedButtonStyle" TargetType="{x:Type Button}" BasedOn="{StaticResource BaseButtonStyle}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border x:Name="OuterBorder" BorderBrush="{DynamicResource GrayBorderBrush}" BorderThickness="2" CornerRadius="5">
<Grid x:Name="LayoutGrid">
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Border x:Name="TopBorder" BorderBrush="{x:Null}" BorderThickness="0" CornerRadius="4,4,0,0" Background="{DynamicResource TopGrayGradientBrush}"/>
<Border x:Name="BottomBorder" BorderBrush="{x:Null}" BorderThickness="0" Grid.Row="1" CornerRadius="0,0,4,4" Background="{DynamicResource BottomGrayGradientBrush}"/>
<ContentPresenter x:Name="contentPresenter" Grid.RowSpan="2" HorizontalAlignment="Center" />
</Grid>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Control.Foreground" TargetName="contentPresenter" Value="{DynamicResource DisabledBrush}"/>
</Trigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Margin" TargetName="OuterBorder" Value="1"/>
<Setter Property="Background" TargetName="TopBorder" Value="{DynamicResource TopGrayGradientBrush}"/>
<Setter Property="Background" TargetName="BottomBorder" Value="{DynamicResource BottomGrayGradientBrush}"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" TargetName="TopBorder" Value="{DynamicResource TopRedGradientBrush}"/>
<Setter Property="Background" TargetName="BottomBorder" Value="{DynamicResource BottomRedGradientBrush}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The problem here is that I've pretty much repeated the entire style, whilst I only want to change the two gradients on the IsMouseOver event
How should I handle this?
PS. I've looked at this WPF -- override style colors, best practice, but I can't figure out the TemplateBinding :/

You can use a technique where you define properties specific to your theme in a separate class and then bind to those properties from your templates. Please see my answer to this question.

How can I make the background color of a node in a TreeView goes all the way out to the right edge?

How can I make the background color of a node in a TreeView goes all the way out to the right edge?
Background
I have a TreeView where all nodes that have children are gray. Leaf nodes have an icon with descriptive text.

If i understand the problem right you are looking to stretch the treeview items.
If that is the case check Here

It's an easy fix. Unfortunately it'll require pretty much code since you'll have to re-template the TreeViewItem. The TreeViewItem's template looks like this
<ControlTemplate TargetType="{x:Type TreeViewItem}">
<Grid>
<Grid.ColumnDefinitions>
<!-- The Expand/Collapse ToggleButton -->
<ColumnDefinition MinWidth="19" Width="Auto"/>
<!-- The TreeViewItem -->
<ColumnDefinition Width="Auto"/>
<!-- The Children -->
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition/>
</Grid.RowDefinitions>
<ToggleButton x:Name="Expander" ClickMode="Press" IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ExpandCollapseToggleStyle}"/>
<Border x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.Column="1" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true">
<ContentPresenter x:Name="PART_Header" ContentSource="Header" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
<ItemsPresenter x:Name="ItemsHost" Grid.ColumnSpan="2" Grid.Column="1" Grid.Row="1"/>
</Grid>
As you can see, the TreeViewItem itself is in Column 1 which has Width set to Auto while the children (ItemsPresenter) is in Grid.Column 1 and 2 and the Column 2 has Width set to *. To get the TreeViewItem itself to get the same Width as its children we can remove the middle Column (Column 1) and just use Grid.Column="1" for both.
Here's the default Template for TreeViewItem with this "Horizontal Stretch" fix. You'll have to add a reference to PresentationFramework.Aero
<Style x:Key="TreeViewItemFocusVisual">
<Setter Property="Control.Template">
<Setter.Value>
<ControlTemplate>
<Rectangle/>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<PathGeometry x:Key="TreeArrow" Figures="M0,0 L0,6 L6,0 z"/>
<Style x:Key="ExpandCollapseToggleStyle" TargetType="{x:Type ToggleButton}">
<Setter Property="Focusable" Value="False"/>
<Setter Property="Width" Value="16"/>
<Setter Property="Height" Value="16"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type ToggleButton}">
<Border Background="Transparent" Height="16" Padding="5,5,5,5" Width="16">
<Path x:Name="ExpandPath" Data="{StaticResource TreeArrow}" Fill="Transparent" Stroke="#FF989898">
<Path.RenderTransform>
<RotateTransform Angle="135" CenterY="3" CenterX="3"/>
</Path.RenderTransform>
</Path>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Stroke" TargetName="ExpandPath" Value="#FF1BBBFA"/>
<Setter Property="Fill" TargetName="ExpandPath" Value="Transparent"/>
</Trigger>
<Trigger Property="IsChecked" Value="True">
<Setter Property="RenderTransform" TargetName="ExpandPath">
<Setter.Value>
<RotateTransform Angle="180" CenterY="3" CenterX="3"/>
</Setter.Value>
</Setter>
<Setter Property="Fill" TargetName="ExpandPath" Value="#FF595959"/>
<Setter Property="Stroke" TargetName="ExpandPath" Value="#FF262626"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<Style x:Key="StretchTreeViewItemStyle"
TargetType="{x:Type TreeViewItem}"
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="HorizontalContentAlignment" Value="{Binding HorizontalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="VerticalContentAlignment" Value="{Binding VerticalContentAlignment, RelativeSource={RelativeSource AncestorType={x:Type ItemsControl}}}"/>
<Setter Property="Padding" Value="1,0,0,0"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
<Setter Property="FocusVisualStyle" Value="{StaticResource TreeViewItemFocusVisual}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TreeViewItem}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition MinWidth="19" Width="Auto"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition/>
</Grid.RowDefinitions>
<ToggleButton x:Name="Expander" ClickMode="Press" IsChecked="{Binding IsExpanded, RelativeSource={RelativeSource TemplatedParent}}" Style="{StaticResource ExpandCollapseToggleStyle}"/>
<Border x:Name="Bd" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" Grid.Column="1" Padding="{TemplateBinding Padding}" SnapsToDevicePixels="true">
<ContentPresenter x:Name="PART_Header" ContentSource="Header" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
</Border>
<ItemsPresenter x:Name="ItemsHost" Grid.Column="1" Grid.Row="1"/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsExpanded" Value="false">
<Setter Property="Visibility" TargetName="ItemsHost" Value="Collapsed"/>
</Trigger>
<Trigger Property="HasItems" Value="false">
<Setter Property="Visibility" TargetName="Expander" Value="Hidden"/>
</Trigger>
<Trigger Property="IsSelected" Value="true">
<Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.HighlightBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.HighlightTextBrushKey}}"/>
</Trigger>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsSelected" Value="true"/>
<Condition Property="IsSelectionActive" Value="false"/>
</MultiTrigger.Conditions>
<Setter Property="Background" TargetName="Bd" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
</MultiTrigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="VirtualizingStackPanel.IsVirtualizing" Value="true">
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<VirtualizingStackPanel/>
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
</Style>
And then you can use it like this
<TreeView ...>
<TreeView.ItemContainerStyle>
<Style TargetType="{x:Type TreeViewItem}" BasedOn="{StaticResource StretchTreeViewItemStyle}">
<!-- Add your own setters if applicable -->
</Style>
</TreeView.ItemContainerStyle>
</TreeView>