Enumerate and apply WPF styles programmatically

Question

I have a WPF button as such

<Button Name="HelloWorldButton"
        Width="100"
        Height="100"
        HorizontalAlignment="Center"
        VerticalAlignment="Center"
        Style="{StaticResource TileButton}">
    Hello world
</Button>

Using WPF styling I have applied a style template as shown below

<Style x:Key="TileButton" TargetType="Button">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="Button">
                <Border x:Name="focusRect"
                        Margin="-6"
                        BorderThickness="6">
                    <ContentPresenter />
                    <Border.BorderBrush>
                        <SolidColorBrush x:Name="focusRectBrush" Color="Transparent" />
                    </Border.BorderBrush>
                    <VisualStateManager.VisualStateGroups>
                        <VisualStateGroup x:Name="CommonStates">
                            <VisualState x:Name="Normal" />
                            <VisualState x:Name="MouseOver">
                                <Storyboard>
                                    <ColorAnimation Duration="0"
                                                    Storyboard.TargetName="focusRectBrush"
                                                    Storyboard.TargetProperty="Color"
                                                    To="Red" />
                                </Storyboard>
                            </VisualState>
                            <VisualState x:Name="Pressed">
                                <Storyboard>
                                    <ColorAnimation Duration="0"
                                                    Storyboard.TargetName="focusRectBrush"
                                                    Storyboard.TargetProperty="Color"
                                                    To="White" />
                                </Storyboard>
                            </VisualState>
                        </VisualStateGroup>
                    </VisualStateManager.VisualStateGroups>
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

I would now like to apply the MouseOver VisualState programmatically. I have looked through the HelloWorldButton.Style property and cannot see any obvious way of achieving this.

Note: Obviously I understand that it would be trivial to programmatically add a border to the button directly without using the declared XAML style sheet, however in my scenario this is not a viable approach.

Answer 1

Finally worked it out.

The code I was looking for was as simple as

VisualStateManager.GoToState(HelloWorldButton, "MouseOver", true);

Answer 2

I added:

<Button Name="HelloWorldButton"
    Width="100"
    Height="100"
    HorizontalAlignment="Center"
    VerticalAlignment="Center"
    Style="{StaticResource TileButton}" MouseEnter="HelloWorldButton_MouseEnter">

I then duplicated another style "Tilebutton2" style where I change the color red to green, and in the MouseEnter event I put in:

 HelloWorldButton.Style = this.Resources["TileButton2"] as Style;

Now when you mouse over the button the border is now green.