Binding doesn't work for TypeInfo Class.

Question

I create 2 classes (TestClass1 and TestClass2 ) and add them to Page as resources. Property of TestClass2 binds to property of TestClass2 but this doesn't work.

 public class TestClass1
    {
        public TypeInfo Property
        {
            get
            { return typeof(string).GetTypeInfo(); }
        }
    }

    public class TestClass2:DependencyObject
    {
        public TypeInfo Property
        {
            get { return (TypeInfo)GetValue(PropertyProperty); }
            set { SetValue(PropertyProperty, value); }
        }
        
        public static readonly DependencyProperty PropertyProperty =
            DependencyProperty.Register("Property", typeof(TypeInfo), typeof(TestClass2), new PropertyMetadata(null));

        public string PropertyString
        {
            get
            {
                if (this.Property != null)
                {
                    return this.Property.FullName;
                }
                else
                {
                    return "Property didn't set";
                }               
            }
        }        
    }

XAML:

<Page.Resources>
        <local:TestClass1 x:Key="Res1"/>
        <local:TestClass2 x:Key="Res2" Property="{Binding Source={StaticResource Res1}, Path=Property}"/>
    </Page.Resources>
    <Grid Background="{StaticResource ApplicationPageBackgroundBrush}">
        <TextBlock Name="tb" Text="{Binding Source={StaticResource Res2}, Path=PropertyString}"/>
    </Grid>

When I run this code, textblock shows text "Property didn't set". If I change type of properties from TypeInfo to custom class, everything works fine.

Is it correct behavior?

Answer 1

I'm looking into this.  One interesting thing I found when I turned on binding logging:

Error: Converter failed to convert value of type 'System.RuntimeType, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' to type 'TypeInfo'; BindingExpression: Path='Property' DataItem='test_TypeInfo_Binding.TestClass1'; target element is 'test_TypeInfo_Binding.TestClass2' (Name='null'); target property is 'Property' (type 'TypeInfo').

I'll continue to investigate and update you when I know more.

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Matt Small - Microsoft Escalation Engineer - Forum Moderator

Answer 2

This is a known problem.  The suggestion is to try using Object as the property type instead of TypeInfo.

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Matt Small - Microsoft Escalation Engineer - Forum Moderator