Question

I have 2 styles for a button. The first one is for normal state and the second is for mouseOver state. How can I change the button style when the mouse enters it? In Blend I tried to create a storyboard and change the style but nothing happened.

Answer 1

You could bind the Style property to IsMouseOver and use a generic “true value”/”false value” converter.

You can specify the converter like this

<Window.Resources>
    <Style TargetType="Button" x:Key="normalStyle">
        <Setter Property="Foreground" Value="Green"/>
    </Style>
    <Style TargetType="Button" x:Key="mouseOverStyle">
        <Setter Property="Foreground" Value="Red"/>
    </Style>
    <converters:BooleanObjectConverter FalseValue="{StaticResource normalStyle}"
                                       TrueValue="{StaticResource mouseOverStyle}"
                                       x:Key="styleConverter"/>
</Window.Resources>

And then bind Style to IsMouseOver

<Button Style="{Binding RelativeSource={RelativeSource Self},
                        Path=IsMouseOver,
                        Converter={StaticResource styleConverter}}" 
        ... />

BooleanObjectConverter

public class BooleanObjectConverter : IValueConverter
{
    public object TrueValue { get; set; }
    public object FalseValue { get; set; }

    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if ((bool)value == true)
        {
            return TrueValue;
        }
        return FalseValue;
    }
    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotSupportedException();
    }
}