flutter

screen template.dart

import 'package:flutter/material.dart';

class GoodListScreen extends StatefulWidget {
  static const routeName = 'GoodListScreen';
  GoodListScreen({Key key}) : super(key: key);

  _GoodListState createState() => _GoodListState();
}

class _GoodListState extends State<GoodListScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
        resizeToAvoidBottomInset: false,
        appBar: AppBar(
          title: Text("Title"),
          actions: <Widget>[
            // action button
            IconButton(
              icon: Icon(Icons.delete),
              onPressed: () {},
            )
          ],
        ),
        body: Builder(builder: (BuildContext context) {
          return Column(
            children: <Widget>[],
          );
        }));
  }
}

snippet.dart

 
 //rectangle box
 
Container(
  height: 80.0,
  width: 200.0,
  color: Colors.transparent,
  child: Container(
    decoration: BoxDecoration(
        color: Colors.white,
        borderRadius: BorderRadius.all(Radius.circular(10))),
    child: Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: <Widget>[

      ],
    ),
  ))
 
 
 //drop down
 
child: new DropdownButtonHideUnderline(
    child: new DropdownButton(
      isDense: true,
      value: dropdownValue,
      onChanged: (String newValue) {
        this.setState(() {
          this.dropdownValue = newValue;
        });
      },
      items: <String>['One', 'Two', 'Free', 'Four']
          .map<DropdownMenuItem<String>>((String value) {
        return DropdownMenuItem<String>(
          value: value,
          child: Text(value),
        );
      }).toList(),
    ),
  ),


/// border beveled
          Material(
                elevation: 16.0,
                shape: BeveledRectangleBorder(
                  borderRadius:
                      BorderRadius.only(topLeft: Radius.circular(46.0)),
                ),
                child: widget.child,
              ),