createState method

  1. @override
State<StatefulWidget> createState ()
override

Creates the mutable state for this widget at a given location in the tree.

Subclasses should override this method to return a newly created instance of their associated State subclass:

@override
_MyState createState() => _MyState();

The framework can call this method multiple times over the lifetime of a StatefulWidget. For example, if the widget is inserted into the tree in multiple locations, the framework will create a separate State object for each location. Similarly, if the widget is removed from the tree and later inserted into the tree again, the framework will call createState again to create a fresh State object, simplifying the lifecycle of State objects.

Implementation 

@override
State<StatefulWidget> createState() {
  // The `time` mode and `dateAndTime` mode of the picker share the time
  // columns, so they are placed together to one state.
  // The `date` mode has different children and is implemented in a different
  // state.
  if (mode == CupertinoDatePickerMode.time || mode == CupertinoDatePickerMode.dateAndTime)
    return _CupertinoDatePickerDateTimeState();
  else
    return _CupertinoDatePickerDateState();
}