Full width DropdownButton with adjust dropdown arrow icon in Flutter

Just adding isExpanded:true to the DropdownButton

  Widget example() {
    return DropdownButton(
          isExpanded: true,
            items: const [
               DropdownMenuItem(child: Text("Abc")),
               DropdownMenuItem(child: Text("Xyz")),
            ],
            hint: const Text("Select City"),
            onChanged: null
        );
  }