Using TextEditingController to pass the item in dropdown, in flutter

Question

I have built a dropdown which has a dropdown list. The item that is selected from the list should be passed to another page, hence, I have used the TextEditingController variable to do that. But the problem is that the dropdown button doesn't allow us to use the TextEditingController. My code is below:

TextEditingController _name = new TextEditingController();
String ? valueChoose;
List listItem = ["A", "B", "C", "D"];


 DropdownButton<String>(
  underline: SizedBox(),
  hint: Text('Example'),
  dropdownColor: Colors.white,
  isExpanded: true,
  icon: Icon(Icons.arrow_drop_down),
  iconSize: 40.0,
  value: valueChoose,
  onChanged: (String ? newValue) {
  setState(() {
  valueChoose = newValue!;
     });
    },
    items: listItem.map<DropdownMenuItem<String>>((valueItem){
    return DropdownMenuItem(
      value: valueItem,
       child: Text(valueItem),
    );
   }).toList(),
  ),

Please suggest how can I achieve this. Thanks in advance!