如何将样式绑定到控件

Question

I try to make blinking style fro Image, and I intend to assign this style dynamically and assign this style for some image that has dependency property HasError, when HasErro=True the image blinking otherwise not blinking and style set to null.

here is my style that works correctly:

<Style x:Key="myImageAnimateStyle">
        <Style.Triggers>
            <EventTrigger RoutedEvent="FrameworkElement.Loaded">
                <BeginStoryboard>
                    <Storyboard>
                        <DoubleAnimation Storyboard.TargetProperty="(UIElement.Opacity)"
                           BeginTime="0:0:0" Duration="0:0:0.5"
                           From="1.0" To="0.0" RepeatBehavior="Forever" AutoReverse="True"/>

                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Style.Triggers>
    </Style>

and this is my style binding:

<Image x:Name="imgErro" Style="{Binding HasError, Converter={StaticResource ErrorBooleanAnimate}, ElementName=userControl}"/>

and this is my Value converter with two solution but doesn't work:

    public class ErrorBooleanAnimate : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (!(value is bool?))
            return null;

        if ((bool)value == true)
        {
            // Solution 1
            //return "{DynamicResource myImageAnimateStyle}";

            // Solution 2
            Style newStyle = (Style)Application.Current.TryFindResource("myImageAnimateStyle");
            return newStyle;
        }
        else
        {
            return null;
        }
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

what is the best solution for this issue?

Answer 1

You need to define resource under App resources to make your code work.

Still if you want to define it under UserControl resources, you need to pass userControl instance to converter and search in it's resources.

(Style)userControl.TryFindResource("myImageAnimateStyle");

Answer 2

You can pass the style to the converter:

<Image Style="{Binding HasError,
                       Converter={StaticResource ErrorBooleanAnimate},
                       ConverterParameter={StaticResource myImageAnimateStyle},
                       RelativeSource={RelativeSource Self}}"/>

Just return parameter in the converter.