Flutter Development Series

 final prefs = await SharedPreferences.getInstance(); await prefs.setString('username', 'Ankur'); print(prefs.getString('username'));

 ScaffoldMessenger.of(context).showSnackBar(   SnackBar(content: Text("Saved successfully!")), );

  GestureDetector detects touch interactions (tap, double-tap, swipe, etc.) Example: GestureDetector( onTap: () { print("Tapped!"); }, child: Container( color: Colors.blue, child: Text("Tap Me"), ), );

 Each widget in Flutter receives constraints from its parent (min and max width/height). The widget must fit inside those constraints. Example: Container( constraints: BoxConstraints(maxWidth: 200), child: Text("Hello World"), );

 Both are widgets to handle asynchronous data. FutureBuilder – For one-time data (Future) FutureBuilder( future: getData(), builder: (context, snapshot) { if (snapshot.hasData) return Text(snapshot.data); return CircularProgressIndicator(); }, ); StreamBuilder – For continuous data (Stream) StreamBuilder( stream: counterStream, builder: (context, snapshot) { if (snapshot.hasData) return Text('${snapshot.data}'); return CircularProgressIndicator(); }, );

  ListView is used for displaying a scrollable list of items. Types: ListView() – Default constructor ListView.builder() – Efficient for long lists ListView.separated() – With separators ListView.custom() – Custom behavior Example: ListView.builder( itemCount: items.length, itemBuilder: (context, index) { return ListTile(title: Text(items[index])); }, );