单击下拉菜单项后如何显示自定义值

Question

For a DropDown when I select any purticular option that value gets displayed in the dropDown.

How do I effectively change what is displayed once a purticular drop down menu item is clicked on.

As you can see from the below images. In the Brands Dropdown once I select an item its value gets displayed. However, I would like to change the value that is displayed.

How do I accomplish that? Thanks.

Answer 1

EDITED please pay attention on hint property and this.hintValue

You need to set State in onChanged event and associate value to new value grabbed from onchanged like this

onChanged: (String newValue) {
    setState(() {
      this.hintValue = newValue;
    });
  },

while:

 return DropdownButton<String>(
  value: dropdownValue,
  hint: Text("${this.hintValue}"),
  icon: Icon(Icons.arrow_downward),
  iconSize: 24,

fullcode will be like this:

class DropDownWidget extends StatefulWidget {

  DropDownWidget({Key key}) : super(key: key);

  @override
  _DropDownWidgetState createState() => _DropDownWidgetState();
}

/// This is the private State class that goes with MyStatefulWidget.
class _DropDownWidgetState extends State<DropDownWidget> {
  String dropdownValue = 'One';
  String hintValue;
  @override
  Widget build(BuildContext context) {
    return DropdownButton<String>(
      value: dropdownValue,
      hint: Text("${this.hintValue}"),
      icon: Icon(Icons.arrow_downward),
      iconSize: 24,
      elevation: 16,
      style: TextStyle(color: Colors.deepPurple),
      underline: Container(
        height: 2,
        color: Colors.deepPurpleAccent,
      ),
      onChanged: (String newValue) {
        setState(() {
          this.hintValue = newValue;
        });
      },
      items: <String>['One', 'Two', 'Free', 'Four']
          .map<DropdownMenuItem<String>>((String value) {
        return DropdownMenuItem<String>(
          value: value,
          child: Text(value),
        );
      }).toList(),
    );
  }
}

reference from: flutter docs