dart:async

StreamSubscription<T> class

A subscription on events from a Stream.

When you listen on a Stream using Stream.listen, a StreamSubscription object is returned.

The subscription provides events to the listener, and holds the callbacks used to handle the events. The subscription can also be used to unsubscribe from the events, or to temporarily pause the events from the stream.

Example:

final stream = Stream.periodic(const Duration(seconds: 1), (i) => i * i)
    .take(10);

final subscription = stream.listen(print); // A StreamSubscription<int>.

To pause the subscription, use pause.

// Do some work.
subscription.pause();
print(subscription.isPaused); // true

To resume after the pause, use resume.

// Do some work.
subscription.resume();
print(subscription.isPaused); // false

To cancel the subscription, use cancel.

// Do some work.
subscription.cancel();

Constructors

StreamSubscription()

Properties

hashCode → int

read-only, inherited

The hash code for this object.

isPaused → bool

read-only

Whether the StreamSubscription is currently paused.

runtimeType → Type

read-only, inherited

A representation of the runtime type of the object.

Methods

asFuture<E>([E? futureValue]) → Future<E>

Returns a future that handles the onDone and onError callbacks.

cancel() → Future<void>

Cancels this subscription.

noSuchMethod(Invocation invocation) → dynamic

inherited

Invoked when a non-existent method or property is accessed.

onData(void handleData(T data)?) → void

Replaces the data event handler of this subscription.

onDone(void handleDone()?) → void

Replaces the done event handler of this subscription.

onError(Function? handleError) → void

Replaces the error event handler of this subscription.

pause([Future<void>? resumeSignal]) → void

Requests that the stream pauses events until further notice.

resume() → void

Resumes after a pause.

toString() → String

inherited

A string representation of this object.

Operators

operator ==(Object other) → bool

inherited

The equality operator.