Class MessageDescriptor

Describes a message type.

Inheritance
System.Object
DescriptorBase
MessageDescriptor
Implements
Inherited Members
System.Object.ToString()
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
Namespace: Google.Protobuf.Reflection
Assembly: Google.Protobuf.dll
Syntax
public sealed class MessageDescriptor : DescriptorBase, IDescriptor

Properties

ClrType

The CLR type used to represent message instances from this descriptor.

Declaration
public Type ClrType { get; }
Property Value
Type Description
System.Type
Remarks

The value returned by this property will be non-null for all regular fields. However, if a message containing a map field is introspected, the list of nested messages will include an auto-generated nested key/value pair message for the field. This is not represented in any generated type, so this property will return null in such cases.

For wrapper types (StringValue and the like), the type returned here will be the generated message type, not the native type used by reflection for fields of those types. Code using reflection should call Google.Protobuf.Reflection.MessageDescriptor.IsWrapperType to determine whether a message descriptor represents a wrapper type, and handle the result appropriately.

ContainingType

Declaration
public MessageDescriptor ContainingType { get; }
Property Value
Type Description
MessageDescriptor

If this is a nested type, get the outer descriptor, otherwise null.

CustomOptions

The (possibly empty) set of custom options for this message.

Declaration
[Obsolete("CustomOptions are obsolete. Use GetOption")]
public CustomOptions CustomOptions { get; }
Property Value
Type Description
CustomOptions

EnumTypes

Declaration
public IList<EnumDescriptor> EnumTypes { get; }
Property Value
Type Description
System.Collections.Generic.IList<EnumDescriptor>

An unmodifiable list of this message type's enum types.

Extensions

An unmodifiable list of extensions defined in this message's scope. Note that some extensions may be incomplete (FieldDescriptor.Extension may be null) if they are declared in a file generated using a version of protoc that did not fully support extensions in C#.

Declaration
public ExtensionCollection Extensions { get; }
Property Value
Type Description
ExtensionCollection

Fields

Declaration
public MessageDescriptor.FieldCollection Fields { get; }
Property Value
Type Description
MessageDescriptor.FieldCollection

A collection of fields, which can be retrieved by name or field number.

Name

The brief name of the descriptor's target.

Declaration
public override string Name { get; }
Property Value
Type Description
System.String
Overrides

NestedTypes

Declaration
public IList<MessageDescriptor> NestedTypes { get; }
Property Value
Type Description
System.Collections.Generic.IList<MessageDescriptor>

An unmodifiable list of this message type's nested types.

Oneofs

Declaration
public IList<OneofDescriptor> Oneofs { get; }
Property Value
Type Description
System.Collections.Generic.IList<OneofDescriptor>

An unmodifiable list of the "oneof" field collections in this message type.

Parser

A parser for this message type.

Declaration
public MessageParser Parser { get; }
Property Value
Type Description
MessageParser
Remarks

As MessageDescriptor is not generic, this cannot be statically typed to the relevant type, but it should produce objects of a type compatible with ClrType.

The value returned by this property will be non-null for all regular fields. However, if a message containing a map field is introspected, the list of nested messages will include an auto-generated nested key/value pair message for the field. No message parser object is created for such messages, so this property will return null in such cases.

For wrapper types (StringValue and the like), the parser returned here will be the generated message type, not the native type used by reflection for fields of those types. Code using reflection should call Google.Protobuf.Reflection.MessageDescriptor.IsWrapperType to determine whether a message descriptor represents a wrapper type, and handle the result appropriately.

Methods

FindDescriptor<T>(String)

Finds a nested descriptor by name. The is valid for fields, nested message types, oneofs and enums.

Declaration
public T FindDescriptor<T>(string name)
    where T : class, IDescriptor
Parameters
Type Name Description
System.String name

The unqualified name of the descriptor, e.g. "Foo"
Returns
Type Description
T

The descriptor, or null if not found.
Type Parameters
Name Description
T

FindFieldByName(String)

Finds a field by field name.

Declaration
public FieldDescriptor FindFieldByName(string name)
Parameters
Type Name Description
System.String name

The unqualified name of the field (e.g. "foo").
Returns
Type Description
FieldDescriptor

The field's descriptor, or null if not found.

FindFieldByNumber(Int32)

Finds a field by field number.

Declaration
public FieldDescriptor FindFieldByNumber(int number)
Parameters
Type Name Description
System.Int32 number

The field number within this message type.
Returns
Type Description
FieldDescriptor

The field's descriptor, or null if not found.

GetOption<T>(Extension<MessageOptions, T>)

Gets a single value message option for this descriptor

Declaration
public T GetOption<T>(Extension<MessageOptions, T> extension)
Parameters
Type Name Description
Extension<MessageOptions, T> extension
Returns
Type Description
T
Type Parameters
Name Description
T

GetOption<T>(RepeatedExtension<MessageOptions, T>)

Gets a repeated value message option for this descriptor

Declaration
public RepeatedField<T> GetOption<T>(RepeatedExtension<MessageOptions, T> extension)
Parameters
Type Name Description
RepeatedExtension<MessageOptions, T> extension
Returns
Type Description
RepeatedField<T>
Type Parameters
Name Description
T