XamlMember Class

Reference

Definition

Namespace:: System.Xaml

Assembly:: System.Xaml.dll

Important

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Provides the XAML type system identifier for members of XAML types. The identifier is used by XAML readers and XAML writers during processing of member nodes (when the XAML reader is positioned on a StartMember) and also for general XAML type system logic.

public ref class XamlMember : IEquatable<System::Xaml::XamlMember ^>

public class XamlMember : IEquatable<System.Xaml.XamlMember>

type XamlMember = class
    interface IEquatable<XamlMember>

Public Class XamlMember
Implements IEquatable(Of XamlMember)

Inheritance: Object
XamlMember

Derived: System.Xaml.XamlDirective

Implements: IEquatable<XamlMember>

Remarks

XamlMember can use three methodologies for returning information about a XAML member: standard common language runtime (CLR) reflection; a reference-only reflection technique calling internal APIs that use optimized bit flags; or calling into virtual overrides of the Lookup* API that is provided by possible XamlMember subclasses. For most uses of .NET Framework XAML Services APIs and the XamlMember API, you use the default XAML schema context. The default XAML schema context for .NET Framework XAML Services uses CLR backing for the type system. This enables the XAML readers and XAML writers to work with any type or member that is defined in, or otherwise available to, the CLR and its reflection techniques.

Lookup* APIs and XamlMember Derived Classes

XamlMember defines several virtual members that derived classes might override. These members have names that always start with the string Lookup. The remainder of the API name then references the property that the virtual method influences. For example, a XamlMember derived class might override LookupTargetType to influence what the base-defined property TargetType returns in a derived class. You can predict return values for such properties in XamlMember or existing derived classes by reading the documentation for the relevant Lookup* methods.

The purpose of the Lookup* methods is to provide a XAML type system extension technique that incorporates the XamlMember base class. By deriving from XamlMember and overriding the Lookup virtual members, you can define the concept of a XAML member for a XAML schema in a XAML type system without being tied to the specifics of a backing type system or technology. You can also use a provided XAML schema context under this scheme and still return the results you want.

As an example, consider the XamlMember property IsWritePublic. This property informs callers that operations such as using a XamlWriter for serialization can write a value for this member on a target object. In the default implementation, the determination of whether the member is writable is made by using reflection techniques against the backing CLR Type and its members (the MemberInfo). Therefore, by default, the XAML type system depends on the CLR type system. However, you can remove this dependency for your XAML type system reporting of IsWritePublic by overriding the API LookupIsWritePublic. Within your override, you can use other determinations, such as metadata that is specific to your technology, a primary lookup table that is optimized for a fixed XAML vocabulary, or a variety of other strategies for determining whether a XAML member is writable in your XAML vocabulary.

Constructing XamlMember Without XAML Schema Context

Most constructors of XamlMember require a XamlSchemaContext as part of their initialization. The XamlSchemaContext is also necessary for many internal XamlSchemaContext operations, such as obtaining information that is being forwarded from the backing type. When you are working with the XamlMember API, you typically have a XamlSchemaContext that is available from a surrounding construct such as a XamlWriter. In this case, you can pass the XamlSchemaContext reference through to all XAML type system calls that require a XAML schema context.

One specific constructor, XamlMember(String, XamlType, Boolean), does not require a XamlSchemaContext. However, a XamlMember that is constructed with the XamlMember(String, XamlType, Boolean) signature returns true for IsUnknown.

For a load path that involves XamlObjectWriter, such a member cannot be written into an object graph. Using the .NET Framework XAML services implementation, 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. For example, one or more of the following might be true of your implementation:

The XAML schema context is available later.
You use a member invoker pattern.
You deliberately override XamlObjectWriter.WriteStartMember in a custom XAML writer.

Constructors

XamlMember(EventInfo, XamlSchemaContext, XamlMemberInvoker)	Initializes a new instance of the XamlMember class using CLR type system EventInfo and a XamlSchemaContext, including XamlMemberInvoker information.
XamlMember(EventInfo, XamlSchemaContext)	Initializes a new instance of the XamlMember class using CLR type system EventInfo and a XamlSchemaContext.
XamlMember(PropertyInfo, XamlSchemaContext, XamlMemberInvoker)	Initializes a new instance of the XamlMember class using reflection PropertyInfo and a XamlSchemaContext, including XamlMemberInvoker information.
XamlMember(PropertyInfo, XamlSchemaContext)	Initializes a new instance of the XamlMember class using CLR type system PropertyInfo and a XamlSchemaContext.
XamlMember(String, MethodInfo, MethodInfo, XamlSchemaContext, XamlMemberInvoker)	Initializes a new instance of the XamlMember class for a XamlMember that represents an attachable property, including XamlMemberInvoker information.
XamlMember(String, MethodInfo, MethodInfo, XamlSchemaContext)	Initializes a new instance of the XamlMember class for a XamlMember that represents an attachable property.
XamlMember(String, MethodInfo, XamlSchemaContext, XamlMemberInvoker)	Initializes a new instance of the XamlMember class for a XamlMember that represents an attachable event, including XamlMemberInvoker information.
XamlMember(String, MethodInfo, XamlSchemaContext)	Initializes a new instance of the XamlMember class for a XamlMember that represents an attachable event.
XamlMember(String, XamlType, Boolean)	Initializes a new instance of the XamlMember class using a string name and declaring XamlType information. A XamlMember that is constructed with this signature has significant limitations.

Properties

DeclaringType	Gets the XamlType for the type that declares the member that is associated with this XamlMember.
DeferringLoader	Gets a XamlValueConverter<TConverterBase> object, which is used for deferred loading of XAML declared objects.
DependsOn	Gets a list of XamlMember objects. These report the members where dependency relationships for initialization order exist relative to this XamlMember.
Invoker	Gets the XamlMemberInvoker implementation that is associated with this XamlMember.
IsAmbient	Gets a value that indicates whether this XamlMember is reported as an ambient property.
IsAttachable	Gets a value that indicates whether this XamlMember is an attachable member.
IsDirective	Gets a value that indicates whether this XamlMember is a XAML directive.
IsEvent	Gets a value that indicates whether this XamlMember represents an event member.
IsNameValid	Gets a value that indicates whether this XamlMember is initialized with a valid `xamlName` string as its Name.
IsReadOnly	Gets a value that indicates whether this XamlMember represents a read-only member.
IsReadPublic	Gets a value that indicates whether this XamlMember represents a member with a callable public `get` accessor.
IsUnknown	Gets a value that indicates whether the member is not resolvable by the backing system that is used for type and member resolution.
IsWriteOnly	Gets a value that indicates whether this XamlMember represents a write-only member.
IsWritePublic	Gets a value that indicates whether this XamlMember represents a member that has a callable public `set` accessor.
MarkupExtensionBracketCharacters	Defines the opening and closing bracket characters for a markup extension.
Name	Gets the `xamlName` name string that declares this XamlMember.
PreferredXamlNamespace	Gets the single XAML namespace URI that identifies the primary XAML namespace for this XamlMember.
SerializationVisibility	Gets a DesignerSerializationVisibility value, which indicates how a visual designer should process the member.
TargetType	Gets the XamlType of the type where the XamlMember can exist.
Type	Gets the XamlType of the type that is used by the member.
TypeConverter	Gets a XamlValueConverter<TConverterBase> object, which can be used for type conversion construction of XAML declared objects.
UnderlyingMember	Gets the CLR type system MemberInfo that is available for a member that is constructed by PropertyInfo, MethodInfo, or EventInfo.
ValueSerializer	Gets a XamlValueConverter<TConverterBase> object, which is used for value serialization of XAML declared objects.

Methods

Equals(Object)	Indicates whether the current object is equal to another object.
Equals(XamlMember)	Indicates whether the current object is equal to another object of the same type.
GetHashCode()	Returns the hash code for this object.
GetType()	Gets the Type of the current instance. (Inherited from Object)
GetXamlNamespaces()	Returns a list of XAML namespaces where this XAML member can exist.
LookupCustomAttributeProvider()	When implemented in a derived class, returns an ICustomAttributeProvider implementation.
LookupDeferringLoader()	Returns a XamlValueConverter<TConverterBase> object, which is used for deferred loading of XAML declared objects.
LookupDependsOn()	Returns a list of XamlMember objects. Items in the list report the members where dependency relationships for initialization order exist relative to this XamlMember.
LookupInvoker()	Returns a XamlMemberInvoker that is associated with this XamlMember.
LookupIsAmbient()	Returns whether this XamlMember is reported as an ambient property.
LookupIsEvent()	Returns whether this XamlMember represents an event.
LookupIsReadOnly()	Returns whether this XamlMember represents an intended read-only property.
LookupIsReadPublic()	Returns whether this XamlMember represents a property that has a public `get` accessor.
LookupIsUnknown()	Returns whether this XamlMember represents a member that is not resolvable by the backing system that is used for type and member resolution.
LookupIsWriteOnly()	Returns whether this XamlMember represents a member that has a public `set` accessor but not a public `get` accessor.
LookupIsWritePublic()	Returns whether this XamlMember represents a member that has a public `set` accessor.
LookupMarkupExtensionBracketCharacters()	Returns the opening and closing bracket characters for a markup extension.
LookupTargetType()	Returns the XamlType of the type where the XamlMember can exist.
LookupType()	Returns the XamlType of the type that is used by the member.
LookupTypeConverter()	Returns a type converter implementation that is associated with this XamlMember.
LookupUnderlyingGetter()	Returns a `get` accessor that is associated with this XamlMember.
LookupUnderlyingMember()	Returns a CLR type system MemberInfo that is associated with this XamlMember.
LookupUnderlyingSetter()	Returns a `set` accessor that is associated with this XamlMember.
LookupValueSerializer()	Returns a value serializer implementation that is associated with this XamlMember.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string representation of this XamlMember.

Operators

Equality(XamlMember, XamlMember)	Determines whether two specified XamlMember objects have the same value.
Inequality(XamlMember, XamlMember)	Determines whether two specified XamlMember objects have different values.

Applies to

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