XamlMember.IsUnknown Property


Gets a value that indicates whether the member is not resolvable by the backing system that is used for type and member resolution.

 property bool IsUnknown { bool get(); };
public bool IsUnknown { get; }
member this.IsUnknown : bool
Public ReadOnly Property IsUnknown As Boolean

Property Value

true if the member is not resolvable; false if the member is resolvable.


A XamlMember that is constructed with the XamlMember(String, XamlType, Boolean) signature returns true for IsUnknown.

For a load path that involves XamlObjectWriter, a XamlMember with true for IsUnknown cannot be written into an object graph. Under the default implementations in .NET Framework XAML Services APIs, the XamlObjectWriter.WriteStartMember call throws a XamlObjectWriterException when the relevant XamlMember reports true for IsUnknown.

You should not construct a XamlMember that has a value of true for IsUnknown unless your implementation can handle the exceptions from XamlObjectWriter, or you have other ways to adjust the XamlObjectWriter behavior.

Calling IsUnknown invokes LookupIsUnknown or a specific override of that method.

Applies to