如何在GridView.build上仅突出显示onTaped项？

import 'package:flutter/material.dart';

class GridItem {
  final String title;
  final bool isSelected;

  GridItem({required this.title, this.isSelected = false});
}

class HighlightGridView extends StatefulWidget {
  @override
  _HighlightGridViewState createState() => _HighlightGridViewState();
}

class _HighlightGridViewState extends State<HighlightGridView> {
  List<GridItem> gridItems = [
    GridItem(title: 'Item 1'),
    GridItem(title: 'Item 2'),
    GridItem(title: 'Item 3'),
    // 添加更多的项
  ];

  int selectedItemIndex = -1;

  @override
  Widget build(BuildContext context) {
    return GridView.builder(
      itemCount: gridItems.length,
      gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
        crossAxisCount: 2, // 每行显示的项数
        childAspectRatio: 2 / 1, // 项的宽高比
      ),
      itemBuilder: (context, index) {
        return GestureDetector(
          onTap: () {
            setState(() {
              selectedItemIndex = index;
            });
          },
          child: Container(
            decoration: BoxDecoration(
              color: selectedItemIndex == index
                  ? Colors.blue // 突出显示的颜色
                  : Colors.white,
              border: Border.all(color: Colors.grey),
            ),
            child: Center(
              child: Text(
                gridItems[index].title,
                style: TextStyle(
                  fontWeight:
                      selectedItemIndex == index ? FontWeight.bold : null,
                ),
              ),
            ),
          ),
        );
      },
    );
  }
}