shared_preferences 2.0.13

Flutter plugin for reading and writing simple key-value pairs. Wraps NSUserDefaults on iOS and SharedPreferences on Android.

Shared preferences plugin

Wraps platform-specific persistent storage for simple data (NSUserDefaults on iOS and macOS, SharedPreferences on Android, etc.). Data may be persisted to disk asynchronously, and there is no guarantee that writes will be persisted to disk after returning, so this plugin must not be used for storing critical data.

Supported data types are int, double, bool, String and List<String>.

Usage

To use this plugin, add shared_preferences as a dependency in your pubspec.yaml file.

Examples

Here are small examples that show you how to use the API.

Write data

// Obtain shared preferences.
final prefs = await SharedPreferences.getInstance();

// Save an integer value to 'counter' key. 
await prefs.setInt('counter', 10);
// Save an boolean value to 'repeat' key. 
await prefs.setBool('repeat', true);
// Save an double value to 'decimal' key. 
await prefs.setDouble('decimal', 1.5);
// Save an String value to 'action' key. 
await prefs.setString('action', 'Start');
// Save an list of strings to 'items' key. 
await prefs.setStringList('items', <String>['Earth', 'Moon', 'Sun']);

Read data

// Try reading data from the 'counter' key. If it doesn't exist, returns null.
final int? counter = prefs.getInt('counter');
// Try reading data from the 'repeat' key. If it doesn't exist, returns null.
final bool? repeat = prefs.getBool('repeat');
// Try reading data from the 'decimal' key. If it doesn't exist, returns null.
final double? decimal = prefs.getDouble('decimal');
// Try reading data from the 'action' key. If it doesn't exist, returns null.
final String? action = prefs.getString('action');
// Try reading data from the 'items' key. If it doesn't exist, returns null.
final List<String>? items = prefs.getStringList('items');

Remove an entry

// Remove data for the 'counter' key. 
final success = await prefs.remove('counter');

Testing

You can populate SharedPreferences with initial values in your tests by running this code:

Map<String, Object> values = <String, Object>{'counter': 1};
SharedPreferences.setMockInitialValues(values);

Storage location by platform

Platform	Location
Android	SharedPreferences
iOS	NSUserDefaults
Linux	In the XDG_DATA_HOME directory
macOS	NSUserDefaults
Web	LocalStorage
Windows	In the roaming AppData directory