Flutter PWA中展示原生应用安装提示的最佳方式是什么？

Hey there! Let's work through your questions step by step to get you on the right track:

If you're building a Flutter Web app, that JS code from the Chrome guide belongs in your web/index.html file. You’ve got two easy options:

• Paste the code directly inside a <script> tag at the end of the <body> section (right before </body>) — this ensures it runs only after the page has fully loaded.
• Save the code as a separate .js file (e.g., install-banner.js) in your web folder, then link to it with <script src="install-banner.js"></script> placed in the same end-of-body spot.

For the core Chrome native install banner behavior, you don’t strictly need Flutter code — most of the heavy lifting is handled by the JavaScript in your index.html. That said, if you want to tie this banner to your Flutter app’s logic (like tracking when a user dismisses it, or triggering a custom Dart action after installation), you can bridge the gap using Dart’s dart:js library or the package:js package.

For example, you could set up a JavaScript callback that sends a message to your Flutter code when the banner is displayed, then handle that event in your Dart widgets.

If you’d rather build your own custom popup instead of using Chrome’s native banner, here’s a straightforward way to create an app-wide, dismissible popup using Flutter’s built-in Overlay system:

1. First, define your popup using an OverlayEntry:

OverlayEntry? _popupEntry;

void _showPersistentPopup(BuildContext context) {
  _popupEntry = OverlayEntry(
    builder: (context) => Positioned(
      bottom: 20,
      left: 20,
      right: 20,
      child: Material(
        elevation: 8,
        borderRadius: BorderRadius.circular(8),
        child: Padding(
          padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 12),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: [
              const Text('Would you like to install our app?'),
              IconButton(
                icon: const Icon(Icons.close),
                onPressed: () => _popupEntry?.remove(),
              ),
            ],
          ),
        ),
      ),
    ),
  );
  Overlay.of(context).insert(_popupEntry!);
}

2. To keep the popup persistent across navigation, initialize it in your app’s root widget (like using the builder property of MaterialApp). This way, it stays visible even when users navigate between different routes.

If you want to skip the manual setup, third-party packages like overlay_support simplify creating global overlays with built-in dismissible behavior and animations. Just add the package to your pubspec.yaml, then use its showOverlayNotification method to create a persistent popup users can close with a tap.

内容的提问来源于stack exchange，提问作者alexlipa