How to Listen Charging Status and Battery Level Change in Flutter App
Introduction
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Listening to charging status and battery level changes is a crucial feature in mobile app development, especially for apps that require continuous power supply or have specific power consumption patterns. In Flutter, achieving this is relatively straightforward with the help of plugins and APIs. This article aims to provide a comprehensive guide on how to listen to charging status and battery level changes in a Flutter app.
Understanding Battery and Charging Status
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To start listening to charging status and battery level changes, it is essential to understand the basics of how battery and charging status are represented in Flutter. The `battery` package is a popular choice for this purpose. It provides APIs to fetch the current battery level and charging status.
Implementing Battery and Charging Status Listener
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To implement a battery and charging status listener in Flutter, follow these steps:
Add the `battery` package
First, add the `battery` package to your `pubspec.yaml` file:
“`yml
dependencies:
battery: ^2.1.0
“`
Import the package and initialize it
Then, import the package and initialize it in your Dart file:
“`dart
import ‘package:battery/battery.dart’;
class BatteryStatus {
static void initBattery() {
Battery.bufferSize = 60; // optional
_listenBatteryState();
_listenBatteryLevel();
}
static void _listenBatteryState() {
Battery.batteryState.then((state) {
// Handle battery state
if (state == BatteryState.charging) {
print(‘Battery is charging’);
} else if (state == BatteryState.full) {
print(‘Battery is full’);
} else if (state == BatteryState.discharging) {
print(‘Battery is discharging’);
} else {
print(‘Battery state unknown’);
}
});
}
static void _listenBatteryLevel() {
Battery.batteryLevel.then((level) {
// Handle battery level
print(‘Battery level: $level%’);
});
}
}
“`
Listen to battery level changes
To listen to battery level changes, you can use a `StreamSubscription` to receive updates:
“`dart
import ‘package:battery/battery.dart’;
class BatteryStatus {
StreamSubscription subscription;
static void initBattery() {
subscription = Battery.batteryLevelStream.listen((level) {
print(‘Battery level: $level%’);
});
}
static void cancelSubscription() {
subscription.cancel();
}
}
“`
Conclusion
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Listening to charging status and battery level changes in a Flutter app can be achieved using the `battery` package. By following the steps outlined above, you can easily integrate this feature into your app and provide a better user experience. Remember to handle edge cases and cancel any ongoing subscriptions when not needed.
FAQs
—-
1. What is the purpose of the `battery` package in Flutter?
The `battery` package provides APIs to fetch the current battery level and charging status.
2. How do I add the `battery` package to my Flutter project?
To add the `battery` package, include it in your `pubspec.yaml` file under dependencies.
3. What is the difference between `BatteryState.charging` and `BatteryState.full`?
`BatteryState.charging` indicates the battery is currently being charged, while `BatteryState.full` indicates the battery is fully charged.
4. How do I listen to battery level changes in Flutter?
You can use a `StreamSubscription` to listen to battery level changes using the `batteryLevelStream` provided by the `battery` package.
5. Why is it essential to cancel any ongoing subscriptions when not needed?
Canceling subscriptions when not needed is essential to prevent memory leaks and unnecessary CPU usage.
