The Button class only contains one Dependency Property (DP) for Background, there is no DP for IsMouseOver background.
You have multiple choices, here's a few :
1) Create an Attached Property named IsMouseOverBackground of type Brush and bind to it in your Style.
C#
namespace WpfApp1
{
public class ButtonHelper
{
public static readonly DependencyProperty IsMouseOverBackgroundProperty =
DependencyProperty.RegisterAttached("IsMouseOverBackground", typeof(Brush), typeof(ButtonHelper), new PropertyMetadata(null));
public static Brush GetIsMouseOverBackground(DependencyObject obj)
{
return (Brush)obj.GetValue(IsMouseOverBackgroundProperty);
}
public static void SetIsMouseOverBackground(DependencyObject obj, Brush value)
{
obj.SetValue(IsMouseOverBackgroundProperty, value);
}
}
}
XAML
<!-- ... -->
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="button" Property="Background" Value="{Binding (local:ButtonHelper.IsMouseOverBackground), RelativeSource={RelativeSource TemplatedParent}}" />
</Trigger>
<!-- ... -->
Note the use of parentheses in the Binding, that is needed when binding to an Attached Property.
2) Create a IsMouseOverButton class that inherits from Button, add a DP called IsMouseOverBackground of type Brush and bind to it in your Style.
C#
namespace WpfApp1
{
public class IsMouseOverButton : Button
{
public static readonly DependencyProperty IsMouseOverBackgroundProperty =
DependencyProperty.Register("IsMouseOverBackground", typeof(Brush), typeof(IsMouseOverButton), new PropertyMetadata(null));
public Brush IsMouseOverBackground
{
get { return (Brush)GetValue(IsMouseOverBackgroundProperty); }
set { SetValue(IsMouseOverBackgroundProperty, value); }
}
}
}
XAML
<Style x:Key="MainMenuButtonTemplate" TargetType="{x:Type local:IsMouseOverButton}">
<Style.Setters>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:IsMouseOverButton}">
<Border x:Name="button" CornerRadius="12"
Background="{TemplateBinding Background}"
Width="{TemplateBinding Width}"
Height="{TemplateBinding Height}">
<TextBlock Text="{TemplateBinding Button.Content}"
HorizontalAlignment="Center"
VerticalAlignment="Center"/>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="button" Property="Background" Value="{Binding IsMouseOverBackground, RelativeSource={RelativeSource TemplatedParent}}" />
</Trigger>
<!-- ... -->
<local:IsMouseOverButton x:Name="MyButton"
Style="{StaticResource MainMenuButtonTemplate}"
Margin="0,50,0,0"
Width="auto"
Height="60"
Command="{Binding FindrViewCommand}"
BorderBrush="{x:Null}"
Foreground="White">
<local:IsMouseOverButton.Background>
<ImageBrush ImageSource="https://dummyimage.com/600x400/000/fff" Stretch="None"/>
</local:IsMouseOverButton.Background>
<local:IsMouseOverButton.IsMouseOverBackground>
<ImageBrush ImageSource="https://dummyimage.com/600x401/000/fff" Stretch="None"/>
</local:IsMouseOverButton.IsMouseOverBackground>
</local:IsMouseOverButton>
3) Use the Tag property of your Button to store the IsMouseOver background and bind to it in your Style. I'm not a fan of using Tag property as it's unclear why Tag property is used when another developer reads your code.
