The callback which is called when the stream is canceled.
May be set to null
, in which case no callback will happen.
ControllerCancelCallback get onCancel;
void set onCancel(onCancelHandler());
© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.5.0/dart-async/StreamController/onCancel.html