Flutter for Beginners

Using a controller

When used isolated from a Form, that is, by using the TextField widget, we need to use its controller property to access its value. This is done with the TextEditingController class:

  final _controller = TextEditingController.fromValue(    TextEditingValue(text: "Initial value"),  );

After instantiating the TextEditingController, we set it into the controller property of the TextField widget so that it "controls" the text widget:

TextField(  controller: _controller,);

As you can see, we can set an initial value for the TextField as well.

TextEditingController is notified whenever the TextField widget has a new value. To listen to changes, we need to add a listener to our _controller:

_controller.addListener(_textFieldEvent); ...