Table of Contents

Class MessageBus

Namespace
ReactiveUI
Assembly
ReactiveUI.dll

MessageBus represents an object that can act as a "Message Bus", a simple way for ViewModels and other objects to communicate with each other in a loosely coupled way.

Specifying which messages go where is done via a combination of the Type of the message as well as an additional "Contract" parameter; this is a unique string used to distinguish between messages of the same Type, and is arbitrarily set by the client. 

public class MessageBus : IMessageBus, IEnableLogger
Inheritance
MessageBus
Implements
IEnableLogger
Extension Methods
WhenAnyMixin.WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(TSender?, Expression<Func<TSender, T1>>, Expression<Func<TSender, T2>>, Expression<Func<TSender, T3>>, Expression<Func<TSender, T4>>, Expression<Func<TSender, T5>>, Expression<Func<TSender, T6>>, Expression<Func<TSender, T7>>, Expression<Func<TSender, T8>>, Expression<Func<TSender, T9>>, Expression<Func<TSender, T10>>, Expression<Func<TSender, T11>>, Expression<Func<TSender, T12>>, Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet>)
WhenAnyMixin.WhenAny<TSender, TRet, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>(TSender?, Expression<Func<TSender, T1>>, Expression<Func<TSender, T2>>, Expression<Func<TSender, T3>>, Expression<Func<TSender, T4>>, Expression<Func<TSender, T5>>, Expression<Func<TSender, T6>>, Expression<Func<TSender, T7>>, Expression<Func<TSender, T8>>, Expression<Func<TSender, T9>>, Expression<Func<TSender, T10>>, Expression<Func<TSender, T11>>, Expression<Func<TSender, T12>>, Func<IObservedChange<TSender, T1>, IObservedChange<TSender, T2>, IObservedChange<TSender, T3>, IObservedChange<TSender, T4>, IObservedChange<TSender, T5>, IObservedChange<TSender, T6>, IObservedChange<TSender, T7>, IObservedChange<TSender, T8>, IObservedChange<TSender, T9>, IObservedChange<TSender, T10>, IObservedChange<TSender, T11>, IObservedChange<TSender, T12>, TRet>, bool)

Constructors

MessageBus()

public MessageBus()

Properties

Current

Gets or sets the Current MessageBus.

public static IMessageBus Current { get; set; }

Property Value

IMessageBus

Methods

IsRegistered(Type, string?)

Determines if a particular message Type is registered.

public bool IsRegistered(Type type, string? contract = null)

Parameters

type Type

The Type of the message to listen to.

contract string

A unique string to distinguish messages with identical types (i.e. "MyCoolViewModel") - if the message type is only used for one purpose, leave this as null.

Returns

bool

True if messages have been posted for this message Type.

ListenIncludeLatest<T>(string?)

Listen provides an Observable that will fire whenever a Message is provided for this object via RegisterMessageSource or SendMessage.

public IObservable<T> ListenIncludeLatest<T>(string? contract = null)

Parameters

contract string

A unique string to distinguish messages with identical types (i.e. "MyCoolViewModel") - if the message type is only used for one purpose, leave this as null.

Returns

IObservable<T>

An Observable representing the notifications posted to the message bus.

Type Parameters

T

The type of the message to listen to.

Listen<T>(string?)

Listen provides an Observable that will fire whenever a Message is provided for this object via RegisterMessageSource or SendMessage.

public IObservable<T> Listen<T>(string? contract = null)

Parameters

contract string

A unique string to distinguish messages with identical types (i.e. "MyCoolViewModel") - if the message type is only used for one purpose, leave this as null.

Returns

IObservable<T>

An Observable representing the notifications posted to the message bus.

Type Parameters

T

The type of the message to listen to.

RegisterMessageSource<T>(IObservable<T>, string?)

Registers an Observable representing the stream of messages to send. Another part of the code can then call Listen to retrieve this Observable.

public IDisposable RegisterMessageSource<T>(IObservable<T> source, string? contract = null)

Parameters

source IObservable<T>

An Observable that will be subscribed to, and a message sent out for each value provided.

contract string

A unique string to distinguish messages with identical types (i.e. "MyCoolViewModel") - if the message type is only used for one purpose, leave this as null.

Returns

IDisposable

a Disposable.

Type Parameters

T

The type of the message to listen to.

RegisterScheduler<T>(IScheduler, string?)

Registers a scheduler for the type, which may be specified at runtime, and the contract.

public void RegisterScheduler<T>(IScheduler scheduler, string? contract = null)

Parameters

scheduler IScheduler

The scheduler on which to post the notifications for the specified type and contract. CurrentThreadScheduler by default.

contract string

A unique string to distinguish messages with identical types (i.e. "MyCoolViewModel") - if the message type is only used for one purpose, leave this as null.

Type Parameters

T

The type of the message to listen to.

Remarks

If a scheduler is already registered for the specified runtime and contract, this will overwrite the existing registration.

SendMessage<T>(T, string?)

Sends a single message using the specified Type and contract. Consider using RegisterMessageSource instead if you will be sending messages in response to other changes such as property changes or events.

public void SendMessage<T>(T message, string? contract = null)

Parameters

message T

The actual message to send.

contract string

A unique string to distinguish messages with identical types (i.e. "MyCoolViewModel") - if the message type is only used for one purpose, leave this as null.

Type Parameters

T

The type of the message to send.