Dynamically update style of control in UWP via a trigger

Question

I want to display the style of a control in a template depending on an enum in the used class. I tried to use this to use the enum in XAML and this to create a trigger. The problem is that I cannot use x:Static in UWP and the trigger is never fired. My workaround does not work either.

My class:


//Namespace Enums
public enum ConnectionState
{
    Open,
    Closed,
    Connecting,
    Broken
}

//Namespace Models
public class DatabaseConnection : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    private void OnPropertyChanged([CallerMemberName] string propertyName = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    private ConnectionState _connectionState = ConnectionState.Broken;
    public ConnectionState ConnState
    {
        get => _connectionState;
        set
        {
            if (value != _connectionState)
            {
                _connectionState = value;
                OnPropertyChanged();
                OnPropertyChanged(nameof(ConnStateInt));
                OnPropertyChanged(nameof(InfoBadgeStyle));
            }
        }
    }

    public int ConnStateInt => (int)ConnState;

    public Style InfoBadgeStyle
    {
        get
        {
            return ConnState switch
            {
                ConnectionState.Open => (Style)Application.Current.Resources["SuccessIconInfoBadgeStyle"],
                ConnectionState.Connecting => (Style)Application.Current.Resources["AttentionIconInfoBadgeStyle"],
                ConnectionState.Broken => (Style)Application.Current.Resources["CriticalIconInfoBadgeStyle"],
                _ => (Style)Application.Current.Resources["InformationalIconInfoBadgeStyle"],
            };
        }
    }
}

My template:

<Page.Resources>
    <DataTemplate x:Key="ConnectionTemplate" x:DataType="models:DatabaseConnection">
        <muxc:InfoBadge Style="{x:Bind InfoBadgeStyle}"/>
    </DataTemplate>
</Page.Resources>

How can I update the style with a trigger in UWP?

mm8 · Accepted Answer · 2022-02-03T21:18:12.847

1

It's unclear why you have both an InfoBadgeStyle property and triggers in XAML but if you want your ChangePropertyActions to be able to set the Style property, you should not set the local Style property like this as it will take precedence:

<muxc:InfoBadge ... Style="{x:Bind InfoBadgeStyle}">

So either remove the InfoBadgeStyle property or remove the triggers.

Also note that x:Bind binds OneTime by default so if you want to react to change notifications you should set the Mode to OneWay: Style="{x:Bind InfoBadgeStyle, Mode=OneWay}"

edited Feb 03 '22 at 21:18

answered Jan 18 '22 at 21:38

mm8

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Thank you for your reply. The point because I implemented the triggers is that the solution from you does not work. It is not doing anything on a property change. – tomo_2403 Jan 21 '22 at 20:26
What doesn't work exactly? – mm8 Jan 27 '22 at 17:51
When you change the values of a property, no event for the UI is raised. – tomo_2403 Jan 28 '22 at 20:56
What property are you setting? `InfoBadgeStyle`? – mm8 Jan 31 '22 at 20:08
Yes, I’m using `InfoBadgeStyle`. – tomo_2403 Feb 01 '22 at 21:03
`x:Bind` binds `OneTime` by default so if you want to react to change notifications you should set the `Mode` to `OneWay`: `Style="{x:Bind InfoBadgeStyle, Mode=OneWay}"`. – mm8 Feb 02 '22 at 20:58
That was what I was looking for. Thank you! – tomo_2403 Feb 03 '22 at 18:00

Dynamically update style of control in UWP via a trigger

1 Answers1