CODEWITHSUNDEEP
c#xamlxamarin.forms
trecchino
trecchino

Reputation: 35

Associate the color of a TextColor of a Label in a DataTemplate to a Resource

I have elements of a List inside a StackLayout in Binding. Inside the DataTemplate I have a Label with Gray TextColor. At the press of a button I would like the color of the TextColor to become the color of a resource I have within the application. How could I do?

c#

public class Giorni
{
   public string Color {get;set;}
}

List<Giorni> listgiorni = new List<Giorni>
{
   new Giorni{},
}


BindableLayout,SetItemsSource(StackLayout, listgiorni);

XAML:

   <Application.Resources>
        <Color x:Key="AppPrimaryColor">#1976D2</Color>
   </ApplicationResource>

.....

   <StackLayout>
        <BindableLayout.ItemTemplate>
            <DataTemplate>
               <Label TextColor="Gray" Text="Hello"/>
            </DataTemplate>
        </BindableLayout.ItemTemplate>
    </StackLayout>

Upvotes: 0

Views: 115

Answers (1)

adamm
adamm

Reputation: 919

If I understood you correctly, you want to bind Color from Giorni to Label's TextColor. If that is the case, you need to implement INotifyPropertyChanged in Giorni, and then add binding in XAML <Label TextColor="{Binding Color}" Text="Hello"/>

Here's the complete sample app with button changing the color of the label:

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" x:Class="MyApp.MainPage">
    <StackLayout>
        <StackLayout x:Name="MyStackLayout">
            <BindableLayout.ItemTemplate >
                <DataTemplate>
                    <Label TextColor="{Binding Color}" Text="Hello"/>
                </DataTemplate>
            </BindableLayout.ItemTemplate> 
        </StackLayout>
        <Button Clicked="OnButtonClicked" Text="Change Color!"/>
    </StackLayout>
</ContentPage>

    public class Giorni:INotifyPropertyChanged
    {
        private string _color;
        public string Color
        {
            get { return _color; }
            set { _color = value; NotifyPropertyChanged(); }
        }
        public event PropertyChangedEventHandler PropertyChanged;
        public void NotifyPropertyChanged([System.Runtime.CompilerServices.CallerMemberName] string propertyName = "")
        {
            if (this.PropertyChanged != null)
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
    public partial class MainPage : ContentPage
    {
        List<Giorni> listgiorni = new List<Giorni>
            {
                new Giorni{},
            };
        public MainPage()
        {
            InitializeComponent();
            listgiorni[0].Color = "Gray";
            BindableLayout.SetItemsSource(MyStackLayout, listgiorni);    
        }
        void OnButtonClicked(object sender, EventArgs args)
        {
            listgiorni[0].Color = "Red";
        }

    }

EDIT: After clarification of resource, here's the edited OnButtonClicked. Since your resource is Color, you need to change it to string appropriately, because Giorni's Color is string.

        void OnButtonClicked(object sender, EventArgs args)
        {
            Color color = (Color)Application.Current.Resources["AppPrimaryColor"];
            int red = (int)(color.R * 255);
            int green = (int)(color.G * 255);
            int blue = (int)(color.B * 255);
            listgiorni[0].Color = String.Format("#{0:X2}{1:X2}{2:X2}", red, green, blue );
        }

A better solution would be to change your Giorni's Color property from string to Color type. Then in OnButtonClicked you can just put:

        void OnButtonClicked(object sender, EventArgs args)
        {
            listgiorni[0].Color = (Color)Application.Current.Resources["AppPrimaryColor"];
        }

Upvotes: 1

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