How to define ResourceDictionary by adding Style in Xamarin xaml {GroupStyle}

Question

I'm trying to make something like set atribute to all labels inside a grid

I Know how to make it, just doing this:

<Grid RowSpacing="2" Padding="2,0,2,0">
    <Grid.Resources>
       <ResourceDictionary>
            <Style BasedOn="{StaticResource Font-Awesome}" TargetType="Label"/>
       </ResourceDictionary>
    </Grid.Resources>
        <Label Text="31 &#xf083;" Grid.Column="0" TextColor="#2764B5" XAlign="Start"/>

        <Label Text="91 &#xf083;" Grid.Column="1" TextColor="#A0A1A2" XAlign="Center"/>

        <Label Text="12 &#xf083;" Grid.Column="2" TextColor="#A0A1A2" XAlign="End"/>
</Grid>

But Its Ugly and redundant

I want to do smetthing like

<Grid RowSpacing="2" Padding="2,0,2,0" Style="{StaticResource grd-actions}">
    <Label Text="31 &#xf083;" Grid.Column="0" TextColor="#2764B5" XAlign="Start"/>

    <Label Text="91 &#xf083;" Grid.Column="1" TextColor="#A0A1A2" XAlign="Center"/>

    <Label Text="Compartilhar &#xf083;" Grid.Column="2" TextColor="#A0A1A2" XAlign="End"/>
</Grid>

And On App Static Resources include the ResourceDictionary for the grid, something like:

<Style x:Key="gd-actions" TargetType="Grid">
    <Setter Property="Resources">
      <Setter.Value>
        <ResourceDictionary>
          <Style BasedOn="{StaticResource Font-Awesome}" TargetType="Label"/>
        </ResourceDictionary>
      </Setter.Value>
    </Setter>
</Style>

I've being trying with a lot of ways but it's aways throw some kind of exception!

Can someone help-me Here?

You are wanting to use XAML styles like CSS - but that is not a perfect analog. Your first example (that you dislike) is indeed the proper approach for this. — Keith Rome, Jul 05 '16 at 16:12
I see, so I can't target a style to an grid and change all items inside like CSS ? it would be wonderful to group all styles to affect only inside a view Element as implicit. I really dislike to call an static resource to everything — Nicollas Braga, Jul 05 '16 at 17:49
Styles do not propagate to child elements. `BindingContext` propagates, and availability of the contents of resource dictionaries propagate down the element tree, but not Styles. Ultimately this is because the `Setter` elements in a `Style` need to know what the target element type is, because that's where it will look for the dependency property definitions. CSS works entirely differently. — Keith Rome, Jul 05 '16 at 20:24

score 4 · Accepted Answer · answered Jul 05 '16 at 14:33

I guess the most clean way to do this is by using Explicit Styles with Global Resources. Declare the style for that Labels in Application Resources and then in you label just add the Style Property:

Application:

<Application xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="xforms_test.App">
    <Application.Resources>
        <ResourceDictionary>
            <Style x:Key="labelAquaStyle" TargetType="Label">
                <Setter Property="HorizontalOptions" Value="Center" />
                <Setter Property="TextColor" Value="Aqua" />
            </Style>
        </ResourceDictionary>
    </Application.Resources>
</Application>

And in your page:

<Grid RowSpacing="2" Padding="2,0,2,0">
    <Label Grid.Column="0" Text="These labels" Style="{StaticResource labelAquaStyle}" />
    <Label Grid.Column="1" Text="are demonstrating" Style="{StaticResource labelAquaStyle}" />
    <Label Grid.Column="2" Text="explicit styles" Style="{StaticResource labelAquaStyle}" />
</Grid>

But calling Styles on every element is very boring/redundant do not have any way to make something like CSS styles ? — Nicollas Braga, Jul 05 '16 at 17:52
If the style was Global (you want to use that style in every Label of your App) you could get rid of the Style property on every element, otherwise there is no other way. — jzeferino, Jul 05 '16 at 19:59

How to define ResourceDictionary by adding Style in Xamarin xaml {GroupStyle}

1 Answers1