onCancel property Null safety
read / write
The callback which is called when the stream is canceled.
May be set to null, in which case no callback will happen.
Implementation
abstract FutureOr<void> Function()? onCancel;The callback which is called when the stream is canceled.
May be set to null, in which case no callback will happen.
abstract FutureOr<void> Function()? onCancel;