Usage of own defined DependencyProperty of type bool? failes

Question

Hi,

I have the following definition in a class library

        public static bool? GetGeneralUserFlag ( DependencyObject obj )
        {
            return (bool?)obj.GetValue(GeneralUserFlagProperty);
        }

        public static void SetGeneralUserFlag ( DependencyObject obj, bool? value )
        {
            obj.SetValue(GeneralUserFlagProperty, value);
        }

        public static readonly DependencyProperty GeneralUserFlagProperty =
            DependencyProperty.RegisterAttached("GeneralUserFlag", typeof(bool?), typeof(FrameworkExtension), new PropertyMetadata(null));

I tried to use it in XAML as follows:

    <StackPanel xmlns:cle="using:ClassLibrary.Extensions" cle:FrameworkExtension.GeneralUserFlag="true" />

Compile goes ok, on execution:

An exception of type 'Windows.UI.Xaml.Markup.XamlParseException' occurred in XXX.exe but was not handled in user code

WinRT information: Failed to create a 'Windows.Foundation.IReference`1<Boolean>' from the text 'true'. [Line: 27 Position: 190]

Additional information: Unspecified error

Answer 1

Hi NRN,

Does this work for you if you use a non-nullable bool? If you do the same in your main app rather than in a class library?

Setting nullable properties I custom controls is not a supported scenario. See this thread for a previous discussion of a similar issue.

--Rob