Flutter change TextField border color on focus

4 min read
TextField(
  textAlign: TextAlign.center,
  decoration: InputDecoration(
    hintText: "API Key",
    border: OutlineInputBorder(
      borderRadius: BorderRadius.circular(8),
      borderSide: BorderSide(
        color: Colors.grey,
      ),
    ),
    focusedBorder: OutlineInputBorder(
      borderRadius: BorderRadius.circular(8),
      borderSide: const BorderSide(
        color: Colors.grey, width: 2.0),
      // borderRadius: BorderRadius.circular(25.0),
    ),
  ),
),