Applying a conditional effect to a Label

jholme · March 8

Hello! I am having quite a bit of trouble trying to add a conditional strikethrough effect to a label. The following generates an error "Can't resolved Effects on Label". I am trying to add a strikethrough effect to a label if the operation type is a certain value - otherwise it should just default to MyStyle.

I'm stuck and I would appreciate any tips! Thanks!

       <Label
                        Style="{StaticResource MyStyle}"
                        Text="{Binding Name}">
                        <Label.Triggers>
                            <DataTrigger
                                Binding="{Binding Name.Operation}"
                                TargetType="Label"
                                Value="2">
                                <Setter Property="Effects">
                                    <Setter.Value>
                                        <effects:StrikethoughEffect />
                                    </Setter.Value>
                                </Setter>
                            </DataTrigger>
                        </Label.Triggers>
                    </Label>

igorkr_10 · March 8

Label has a property TextDecorations where you can set strikethrough text. For effects you need to make sure that using of them is right. Check in documentation how to properly use effects.

igorkr_10 · March 8

Also I can't see a link between trigger and Style.
Maybe its better to bind TextDecorations property of Label to property of ViewModel? And when your operation is changing just call OnPropertyChanged for that property?

jholme · March 11

Thank you. However, I do not believe TextDecorations are in the version of Xamarin.Forms I am using (3.2.x).

yelinzh · March 14

You can use TextDecorations property in the version of Xamarin.Forms(3.3.x).

There are to ways to consume the effect :
in xaml

<Entry Text="Effect attached to an Entry" ...>
    <Entry.Effects>
        <local:FocusEffect />
    </Entry.Effects>
    ...
</Entry>

in c#

public HomePageCS ()
{
  ...
  entry.Effects.Add (Effect.Resolve ($"MyCompany.{nameof(FocusEffect)}"));
  ...
}

yelinzh · March 14

I've reproduced the code. There are no 'Effects' in Setter's Property.
You can change the code as follows :

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:EffectsDemo" x:Class="EffectsDemo.HomePage">
    <StackLayout Padding="0,20,0,0">
        <Label Text="Effects Demo - Focus Effect" FontAttributes="Bold" HorizontalOptions="Center">
            <Label.Effects>
                <local:FocusEffect />
            </Label.Effects>
    ...
            <Label.Triggers>
                <DataTrigger TargetType="Label"
                             Value="2">
                    <Setter Property="FontSize">
                        <Setter.Value>
                            24
                        </Setter.Value>
                    </Setter>
                </DataTrigger>
            </Label.Triggers>
        </Label>
    </StackLayout>
</ContentPage>

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Applying a conditional effect to a Label

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