Getting the effective color from styles in code.

[JPfahl]

I am setting the luminosity of the ImageSource in an ImageButton to give the user visual feedback that the button was pressed using the Pressed, Released and Unfocus events. Even though I restore the color to its original value when the press is complete, when the theme changes the color is not set to the new color from the new theme. I am guessing that under the covers the styles setup a binding that is lost when I set the color in code. Is there a way to restore the binding? Is there a way to force the style to apply the color when the theme changes? is there a way to get the effective color from the styles so I can set it myself in code? I use both styles applied using TargetType and styles set using StyleClass.

[stephenquan]

Style apps using XAML has a section on Style Inheritance

Styles can inherit from other styles to reduce duplication and enable reuse. This is achieved by setting the Style.BasedOn property to an existing Style. In XAML, this can be achieved by setting the BasedOn property to a StaticResource markup extension that references a previously created Style.

You can declare Visual States for Normal, Pressed and Focused states and use these visual states to switch between your various styles.

[JPfahl]

I know all that. I use styles extensively but I cannot use a visual state in this case because I am not setting the property to a set value but one calculated from the effective color applied to each image source. So I ask again: Is there a way to restore the binding for a style? Is there a way to force the style to apply the color when the theme changes? is there a way to get the effective color from the styles so I can set it myself in code?

[stephenquan]

I don't fully understand your use case. Some code snippets will go along way to help clarify what you want.

Meanwhile, consider putting a control with that style in your ResourceDictionary. Then, you can just query the colors directly from those controls, for instance:

<ContentPge>
    <ContentPage.Resources>
        <ResourceDictionary>
            <Label x:Key="HeadlineLabel" Style="{StaticResource Headline}" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <!-- ... -->
        <Label TextColor="{Binding TextColor, Source={StaticResource HeadlineLabel}}" />
    <!-- ... -->
</ContentPage>

[JPfahl]

Again the color I'm setting is not a static value it is calculated at runtime per instance. So, is there a way to get the effective color from the styles so I can set it myself in code? Once a property value is set in code it is orphaned from the styles. So when the theme changes the property is not updated by the style.

[JPfahl]

I have found a different way to solve this problem.