如何在flutter中使用文件路径加载图像时显示加载器？

import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:flutter/widgets.dart';

class ImageLoader extends StatefulWidget {
  final String imagePath;

  const ImageLoader({Key key, this.imagePath}) : super(key: key);

  @override
  _ImageLoaderState createState() => _ImageLoaderState();
}

class _ImageLoaderState extends State<ImageLoader> {
  bool _isLoading = true;

  @override
  void initState() {
    super.initState();
    loadImage();
  }

  Future<void> loadImage() async {
    // 模拟加载图像的耗时过程
    await Future.delayed(Duration(seconds: 2));

    setState(() {
      _isLoading = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Container(
      child: _isLoading
          ? CircularProgressIndicator() // 加载器
          : Image.file(File(widget.imagePath)), // 加载图像
    );
  }
}

class MyPage extends StatelessWidget {
  final String imagePath = "/path/to/image.png";

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ImageLoader(imagePath: imagePath),
      ),
    );
  }
}