precached_network_image 1.3.0

Flutter library to load and cache network images to disk and support to precache images to memory in advance to avoid the flash screen caused by the delay time.

example/lib/main.dart

import 'dart:developer';
import 'package:flutter/material.dart';
import 'package:precached_network_image/precached_network_image.dart';

class NewPage extends StatelessWidget {
  const NewPage({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('New Page'),
      ),
      body: Center(
        child: PrecachedNetworkImage(
          url: 'https://picsum.photos/300',
          width: 300,
          height: 300,
          precache: false,
          placeholder: (context, url) => Image.asset(
            'assets/images/avatar_default.png',
          ),
          errorWidget: (context, url, error) {
            log("get image failed code: $error");
            return const Icon(Icons.error);
          },
        ),
      ),
    );
  }
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  void initState() {
    super.initState();
    // PrecachedNetworkImageManager.instance.cleanCaches();
    PrecachedNetworkImageManager.instance.precacheNetworkImages(isLog: true);
  }

  @override
  Widget build(BuildContext context) {
    return DefaultTabController(
      initialIndex: 0,
      length: 2,
      child: Scaffold(
        appBar: AppBar(
          title: const Text('PrecachedNetworkImage'),
          bottom: const TabBar(
            tabs: [
              Tab(icon: Icon(Icons.cloud_outlined)),
              Tab(icon: Icon(Icons.beach_access_sharp)),
            ],
          ),
        ),
        body: TabBarView(
          children: [
            Center(
              child: ElevatedButton(
                onPressed: () {
                  Navigator.push(
                    context,
                    MaterialPageRoute(builder: (context) => const NewPage()),
                  );
                },
                child: const Text('Go to New Page'),
              ),
            ),
            Center(
              child: PrecachedNetworkImage(
                url: 'https://picsum.photos/300',
                width: 300,
                height: 300,
                precache: true,
                placeholder: (context, url) => const Icon(Icons.person),
                errorWidget: (context, url, error) {
                  log("get image failed code: $error");
                  return const Icon(Icons.error);
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

Future<void> main() async {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}