flutter weight demo

flutter sdk:快速下载：https://github.com/flutter/flutter/releases

翻译:

StatelessWidget                 无状态小部件

Stateful                               有状态
Scaffold                               脚手架
repair                                  修理

spec                                     规格
inspector                             检查员
Malformed lineFlutter：   线路格式错误  

Because flutter_app2 depends on flutter_test any from sdk which doesn't exist (the Flutter SDK is not available), version solving failed.

由于flutter_app2依赖于flutter_test任何不存在的sdk（flutter sdk不可用），版本求解失败。

Flutter users should run `flutter packages get` instead of `pub get`.

用户应该运行“Flutter packages get”而不是“pub get”。

import 'package:flutter/material.dart';

void main() {
  runApp(new MaterialApp(
    title: 'Flutter Tutorial',
    home: new Counter(),
  ));
}
class MyButton extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new GestureDetector(
      onTap: () {
        print('MyButton was tapped!');
      },
      child: new Container(
        height: 36.0,
        padding: const EdgeInsets.all(8.0),
        margin: const EdgeInsets.symmetric(horizontal: 8.0),
        decoration: new BoxDecoration(
          borderRadius: new BorderRadius.circular(5.0),
          color: Colors.lightGreen[500],
        ),
        child: new Center(
          child: new Text('Engage'),
        ),
      ),
    );
  }
}
class Counter extends StatefulWidget {
  // This class is the configuration for the state. It holds the
  // values (in this nothing) provided by the parent and used by the build
  // method of the State. Fields in a Widget subclass are always marked "final".

  @override
  _CounterState createState() => new _CounterState();
}

class _CounterState extends State<Counter> {
  int _counter = 0;

  void _increment() {
    setState(() {
      // This call to setState tells the Flutter framework that
      // something has changed in this State, which causes it to rerun
      // the build method below so that the display can reflect the
      // updated values. If we changed _counter without calling
      // setState(), then the build method would not be called again,
      // and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance
    // as done by the _increment method above.
    // The Flutter framework has been optimized to make rerunning
    // build methods fast, so that you can just rebuild anything that
    // needs updating rather than having to individually change
    // instances of widgets.
    return new Row(
      children: <Widget>[
        new RaisedButton(
          onPressed: _increment,
          child: new Text('Increment'),
        ),
        new Text('Count: $_counter'),
      ],
    );
  }
}
class MyButton1 extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return new GestureDetector(
      onTap: (){
        print("on top");
      },
      child: new Container(
        height: 55,
        width: 33,
        padding:  EdgeInsets.all(6),
        margin:  EdgeInsets.all(3),
        decoration: new BoxDecoration(
          borderRadius: new BorderRadius.circular(433),
        ),
        child: new Center(
          child: new Text("ceshi"),
        ),
      ),
    );
  }
}
class Hone extends StatelessWidget{
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return new Scaffold(
      appBar: new AppBar(
        // ignore: argument_type_not_assignable
        leading: new IconButton(
            icon: new Icon(Icons.menu),
            onPressed: null),
      ),
      body:new Center(
        child: new Text("12"),
      )
    );
  }
}