inMilliseconds property
The number of whole milliseconds spanned by this Duration.
The returned value can be greater than 999. For example, a duration of three seconds and 125 milliseconds has 3125 milliseconds.
const duration = Duration(seconds: 3, milliseconds: 125);
print(duration.inMilliseconds); // 3125
Implementation
int get inMilliseconds => _duration ~/ Duration.microsecondsPerMillisecond;