[Bug] DynamicResource not working for custom type property in Xamarin

[MuneeshKumarG]

We have tried to bind dynamic resource for my custom class properties. But DynamicResource working fine for object type property, but not working for double type property. See my code below.

You can confirm the dynamic resource not set for PropertyA, by setting break point for PropertyA property change method.

For PropertyB property change method, break point hit with dynamic resource value.

 <ContentPage.Resources>
        <ResourceDictionary>
            <x:Double x:Key="MediumFont">25</x:Double>
        </ResourceDictionary>
    </ContentPage.Resources>

    <StackLayout>
                
        <local:TestClass >
            <local:TestClass.HintStyle>
                <local:LabelStyle PropertyA="{DynamicResource MediumFont}" PropertyB="{DynamicResource MediumFont}"/>
            </local:TestClass.HintStyle>
        </local:TestClass>
        
    
    </StackLayout>

 public class TestClass :View
    {

        public LabelStyle HintStyle
        {
            get => (LabelStyle)GetValue(HintStyleProperty);
            set => SetValue(HintStyleProperty, value);
        }

        public static readonly BindableProperty HintStyleProperty =
            BindableProperty.Create(nameof(HintStyle), typeof(LabelStyle), typeof(TestClass),
            new LabelStyle(), BindingMode.Default);
    }

    public class LabelStyle :View
    {
        public double PropertyA
        {
            get => (double)GetValue(PropertyAProperty);
            set => SetValue(PropertyAProperty, value);
        }

        public static readonly BindableProperty PropertyAProperty =
           BindableProperty.Create(nameof(PropertyA), typeof(double), typeof(LabelStyle), 
               0d, BindingMode.Default, null, OnPropertyAChanged);
        private static void OnPropertyAChanged(BindableObject bindable, object oldValue, object newValue)
        {
        }

        public object PropertyB
        {
            get => GetValue(PropertyBProperty);
            set => SetValue(PropertyBProperty, value);
        }

        private static readonly BindableProperty PropertyBProperty =
            BindableProperty.Create(nameof(PropertyB), typeof(object), typeof(LabelStyle),
            null, BindingMode.Default, null, OnPropertyBChanged);

        private static void OnPropertyBChanged(BindableObject bindable, object oldValue, object newValue)
        {
        }
    }

Please help me. Why the dynamic resource not working for PropertyA.

[Yuvasrisivakumar]

Any update on this?

[jsuarezruiz]

LabelStyle is a View, but has no Parent set, the Parent doesn’t set his children, context is not propagated. Without it, Dynamic Resources can’t work.

[Yuvasrisivakumar]

Hi,

Thanks for your update, and we have tested our sample with your given solution and it works at our end, but we can't set the parent to the LabelStyle class when we inherit the BindableObject in the LabelStyle class. Can you please share any other solution to this problem?

public class LabelStyle : BindableObject
{
public double PropertyA
{
get => (double)GetValue(PropertyAProperty);
set => SetValue(PropertyAProperty, value);
}

    public static readonly BindableProperty PropertyAProperty =
       BindableProperty.Create(nameof(PropertyA), typeof(double), typeof(LabelStyle),
           0d, BindingMode.Default, null, OnPropertyAChanged);
    private static void OnPropertyAChanged(BindableObject bindable, object oldValue, object newValue)
    {
    }
    public object PropertyB
    {
        get => GetValue(PropertyBProperty);
        set => SetValue(PropertyBProperty, value);
    }

    private static readonly BindableProperty PropertyBProperty =
        BindableProperty.Create(nameof(PropertyB), typeof(object), typeof(LabelStyle),
        null, BindingMode.Default, null, OnPropertyBChanged);

    private static void OnPropertyBChanged(BindableObject bindable, object oldValue, object newValue)
    {
    }
}