What is the style trigger when you are hovering over a button in WPF?

My question is pretty straight forward. I am trying to style the background of a button in WPF when I MouseOver/Hover on the button.

<Style x:Key="StandardButton" TargetType="Button">
    <Style.Triggers>
        <Trigger Property="I开发者_JAVA技巧sMouseOver" Value="true">
            <Setter Property="Background" Value="CornflowerBlue" />
        </Trigger>
    </Style.Triggers>
</Style>

When I MouseOver the button, the background colour briefly changes to CornFlowerBlue, but then changes to the default colours that show when you are remaining over the button for a preiod of time.

What Trigger Property do I need to use to keep the background of the button CornFlowerBlue while I am remaining over the button?

Many Thanks

This the default property of the Button Chrome implmented in the Button. I have removed the Button chrome from the default button template and create my own just see

<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:Microsoft_Windows_Themes="clr-namespace:Microsoft.Windows.Themes;assembly=PresentationFramework.Aero"
x:Class="WpfApplication9.Window1"
x:Name="Window"
Title="Window1"
Width="640" Height="480">
<Window.Resources>
    <Style x:Key="ButtonFocusVisual">
        <Setter Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>
                    <Rectangle Stroke="Black" StrokeDashArray="1 2" StrokeThickness="1" Margin="2" SnapsToDevicePixels="true"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <LinearGradientBrush x:Key="ButtonNormalBackground" EndPoint="0,1" StartPoint="0,0">
        <GradientStop Color="#F3F3F3" Offset="0"/>
        <GradientStop Color="#EBEBEB" Offset="0.5"/>
        <GradientStop Color="#DDDDDD" Offset="0.5"/>
        <GradientStop Color="#CDCDCD" Offset="1"/>
    </LinearGradientBrush>
    <SolidColorBrush x:Key="ButtonNormalBorder" Color="#FF707070"/>
    <Style x:Key="ButtonStyle1" TargetType="{x:Type Button}">
        <Setter Property="FocusVisualStyle" Value="{StaticResource ButtonFocusVisual}"/>
        <Setter Property="Background" Value="{StaticResource ButtonNormalBackground}"/>
        <Setter Property="BorderBrush" Value="{StaticResource ButtonNormalBorder}"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
        <Setter Property="HorizontalContentAlignment" Value="Center"/>
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="Padding" Value="1"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}">
                <Border Background="{TemplateBinding Background}"
                BorderBrush="Black" BorderThickness="2" CornerRadius="5" x:Name="bd">
                        <ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" 
                        Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" 
                        SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" RecognizesAccessKey="True"/>
                        </Border>
                    <ControlTemplate.Triggers>
                        <MultiTrigger>
                            <MultiTrigger.Conditions>
                                <Condition Property="IsMouseOver" Value="True"/>
                            </MultiTrigger.Conditions>
                            <Setter TargetName="bd" Property="Background" Value="#FFF40000"/>
                        </MultiTrigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="#ADADAD"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</Window.Resources>
<Grid x:Name="LayoutRoot">
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="0.048*"/>
        <ColumnDefinition Width="0.952*"/>
    </Grid.ColumnDefinitions>
    <Button HorizontalAlignment="Left" Margin="106.048,102,0,0" Style="{DynamicResource ButtonStyle1}" VerticalAlignment="Top" Width="75" Content="Button" Grid.Column="1"/>
</Grid>