如何更改OutlinedTextField的边框宽度？

import 'package:flutter/material.dart';

class CustomBorder extends ShapeBorder {
  final double borderWidth;
  final Color borderColor;

  CustomBorder({required this.borderWidth, required this.borderColor});

  @override
  EdgeInsetsGeometry get dimensions => EdgeInsets.zero;

  @override
  Path getInnerPath(Rect rect, {TextDirection? textDirection}) => Path();

  @override
  Path getOuterPath(Rect rect, {TextDirection? textDirection}) => Path();

  @override
  void paint(Canvas canvas, Rect rect, {TextDirection? textDirection}) {
    final Paint paint = Paint()
      ..color = borderColor
      ..style = PaintingStyle.stroke
      ..strokeWidth = borderWidth;

    final BorderRadius borderRadius = BorderRadius.circular(4.0);
    final Rect borderRect = borderRadius.resolve(rect);

    canvas.drawRRect(borderRect, paint);
  }
}

OutlinedTextField(
  decoration: InputDecoration(
    border: CustomBorder(borderWidth: 2.0, borderColor: Colors.blue),
  ),
);

OutlinedTextField(
  decoration: InputDecoration(
    border: OutlineInputBorder(
      borderRadius: BorderRadius.circular(4.0),
      borderSide: BorderSide(width: 2.0, color: Colors.blue), // 设置边框宽度和颜色
    ),
  ),
);