import 'package:shared_preferences/shared_preferences.dart';
//存
// 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']);
​
// 取
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');
​
// 删除
final success = await prefs.remove('counter');

复杂类型的存储

final prefs = await SharedPreferences.getInstance();
var infoData = [
    {"name":"zhangsan"},
    12,
    true
]
var str = json.encode(infoData);
await prefs.setString('data', str);
String? xxx = await prefs.getString('data', str);