Images take -1 second to load in Flutter-CodePudding

I'm using precacheImage in my app to load faster my assets. Despite this, my first screen images take less than a second to show, causing a bad user experience. I think that this happens because I'm calling precacheImage in the same screen where I have to show some of the images, but this i the very first screen of the app.
How can i avoid this behaviour? Is there a way to cache the images for the next app opens in order not to wait for them each time the user open the app?

CodePudding user response：

Yes, there is a way to cache the images for the next time the app is opened in Flutter. This can be done using the flutter_cache_manager package, which provides caching functionality for images and other files.

To use this package, first add it to your pubspec.yaml file:

dependencies:
  flutter_cache_manager: ^1.3.1

Then, import the package and use the CachedNetworkImage widget to display the images in your app. This widget automatically uses the cache manager to cache the images, so they will be loaded faster the next time the app is opened.

Here is an example of how you can use the CachedNetworkImage widget to display images in your app:

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

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: CachedNetworkImage(
            imageUrl: 'https://example.com/my_image.png',
            placeholder: (context, url) => CircularProgressIndicator(),
            errorWidget: (context, url, error) => Icon(Icons.error),
          ),
        ),
      ),
    );
  }
}

In the example code above, the CachedNetworkImage widget is used to display the image at the URL https://example.com/my_image.png. This widget automatically uses the cache manager to cache the image, so it will be loaded faster the next time the app is opened.

The placeholder and errorWidget properties of the CachedNetworkImage widget are used to specify what should be displayed while the image is being loaded, and in case of an error, respectively. In this example, a circular progress indicator is shown while the image is being loaded, and an error icon is shown if there is an error loading the image.

You can use the CachedNetworkImage widget in the same way to display any image that you want to cache for faster loading the next time the app is opened.

CodePudding user response：

One way to avoid this behavior is to move the call to precacheImage to a separate function that is called when the app starts. This way, the images will be precached before the first screen is displayed, which should improve the user experience.

Here is an example of how you can do this:

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

void main() {
  // Call the precacheImage function when the app starts
  precacheImage();

  runApp(MyApp());
}

// This function precaches the images that you want to use
void precacheImage() {
  // Create a list of the images you want to precache
  List<String> imagePaths = [
    'assets/my_image1.png',
    'assets/my_image2.png',
    // Add more images here
  ];

  // Precache the images
  imagePaths.forEach((path) {
    precacheImage(Image.asset(path).image, context);
  });
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: Image.asset('assets/my_image1.png'),
        ),
      ),
    );