flutter移动开发（二）

import 'package:city_pickers/city_pickers.dart';

import 'package:flutter/material.dart';
import 'package:flutter_datetime_picker/flutter_datetime_picker.dart';

onPressed: () {
        DatePicker.showDatePicker(context,showTitleActions: true,
                              minTime: DateTime(2018, 3, 5),
                              maxTime: DateTime(2019, 6, 7), 
                              onChanged: (date) {
                                print('change $date');
                              }, 
                              onConfirm: (date) {
                                print('confirm $date');
                              }, 
                              currentTime: DateTime.now(), 
                               locale: LocaleType.zh
         );
    },
    child: Text(
        'show date time picker (Chinese)',
        style: TextStyle(color: Colors.blue),
    ));

class _Animation extends State<AnimateApp> with SingleTickerProviderStateMixin{
  AnimationController controller;
  Animation<double> animation;
  
  @override
  void initState() {
    //初始化AnimationController对象
      controller=AnimationController(
        const Duration(milliseconds: 500),
        vsync: this
  	 );
    //通过tween对象，创建animation对象
    animation = Tween(begin: 50.0,end: 200.0).animate(controller)
      ..addlistener((){
        setState(() {});
      })
      //添加状态监听，检测动画是否播放完成
      ...addStatusListener((status){
        if(status == AnimationStatus.completed){
          controller.reverse();
        } else if (status == AnimationStatus.dismissed){
          controller.forward();
        }
      })
      
    //执行动画
    controller.forward();
  }

  @override
  void dispose() {
    super.dispose();
    //销毁控制器，释放资源
    controller.dispose();
  }
}

dependencies:
     flutter_vallains: ^1.2.1

import 'package:flutter_villains/villain.dart'

import 'package:graphql_flutter/graphql_flutter.dart';
import 'package:tinylearn_client/PostsData.dart';//导入模型文件

final _uri = 'http://10.0.0.10:4444/'; //接口地址

Future<PostsData> _postsData;

  @override
  void initState() {
    
    final client = GraphQLClient(
      cache: InMemoryCache(),
      link: HttpLink(uri: _uri)
    );

    _postsData = _createPostsData(client);
    super.initState();
  }

 Future<PostsData> _createPostsData(GraphQLClient client) async {
        
    final result = await client.query(QueryOptions(
      documentNode: gql(r'''
        query {
          posts {
            id
            created
            content
          }
        }
      '''),
    ));
    if (result.hasException) throw result.exception;
    return PostsData.fromMap(result.data);
  }

dependencies:
    shared_preferences

import 'packages:shared_preferences/shared_preferences.dart'

//存数据
Future saveString() async(){
    SharedPreferences sharedPreferences=await SharedPreferences.getInstance();
    sharedPreferences.setString(
       STORAGE_KEY, _textFieldController.value.text.toString()
    );
}
//取数据
Future getString() async(){
    SharedPreferences sharedPreferences=await SharedPreferences.getInstance();
    setState(
       _storageString = sharedPreferences.getString(STORAGE_KEY);
    );//把取出的数据保存到变量中
}
//删除数据
SharedPreferences sharePreferences = await SharedPreferences.getInstance();
sharePreferences.remove(key);

dependencies:
    path_provider: ^0.5.0

import 'package:sqflite/sqflite.dart';

import 'package:provider/provider.dart';

MultiProvider(
  providers: [
    Provider<Something>(create: (_) => Something()),
    Provider<SomethingElse>(create: (_) => SomethingElse()),
    Provider<AnotherThing>(create: (_) => AnotherThing()),
  ],
  child: someWidget,
)

import 'package:fish_redux/fish_redux.dart';

routes:{
   "new_page":(context) => NewRoute(),
    ... // 省略其它路由注册信息
  } ,

Navigator.push(
  context,
  MaterialPageRoute(
    builder: (context) {
      return TipRoute(
        // 路由参数
        text: "我是提示xxxx",
      );
    },
  ),
);
//在路由页添加返回函数
Navigator.pop(context, "我是返回值"),

Future pushNamed(BuildContext context, String routeName,{Object arguments})

class EchoRoute extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    //通过RouteSetting对象获取路由参数  
    var args=ModalRoute.of(context).settings.arguments;
    //...省略无关代码
  }
}

Navigator.of(context).pushNamed("new_page", arguments: "hi");

Navigator.of(context).pushNamed('a_router_widget');
Navigator.of(context).pushReplacementNamed('d_router_widget');
Navigator.of(context).popAndPushNamed('d_router_widget');
Navigator.of(context).pushNamedAndRemoveUntil('d_router_widget', (Route<dynamic> route) => false);

Navigator.of(context).maybePop();
Navigator.of(context).canPop();
Navigator.of(context).pop();
Navigator.popUntil(context, ModalRoute.withName('a_router_widget'));

var today = DateTime.now()//获取当前时间
DateTime victoryDay = new DateTime(1992,9,9)  //创建指定时间
DateTime.parse(string)//字符串转datetime
formatDate(DateTime,[yyyy,'-',mm,'-',dd]);//datetime转字符串
fromMillisecondsSinceEpoch//时间戳转datetime
today.millisecondsSinceEpoch//datetime转时间戳
today.isBefore(date)//时间比较 在之前
today.isAfter(date)//时间比较 在之后
today.isAtSameMomentAs(date)//时间比较 是否相等
compareTo(date)//大于返回1，等于返回0，小于返回-1
today.difference(date)//两个时间相差 小时数
today:add(new Duration(days: 5));//时间加5天
today.subtract(new Duration(days: 5))//时间减五天
today.timeZoneOffset//返回utc与本地时差小时数
today.year//返回年year、月month、日day、时hour、分minute、秒second、毫秒millisecond、微秒microsecond
today.weekday//返回星期几
//计算时间
Duration timeremain = new Duration(days:2,hours:56,minutes:14);//104:14:00

import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';

new StaggeredGridView.countBuilder(
  crossAxisCount: 4,
  itemCount: 8,
  itemBuilder: (BuildContext context, int index) => new Container(
      color: Colors.green,
      child: new Center(
        child: new CircleAvatar(
          backgroundColor: Colors.white,
          child: new Text('$index'),
        ),
      )),
  staggeredTileBuilder: (int index) =>
      new StaggeredTile.count(2, index.isEven ? 2 : 1),
  mainAxisSpacing: 4.0,
  crossAxisSpacing: 4.0,
)

import 'package:flutter/service.dart'

import 'package:flutter_clipboard_manager/flutter_clipboard_manager.dart'

//定义函数，写入剪贴板
static Future<bool> copyToClipboard(String text) asyc{
    return FlutterClipboardManager.copyToClipBoard(text).then((result){
        
    });//支持调用.then方法
}
//从剪贴板导出
static Future<bool> copyFromClipboard(String text) asyc{
    return FlutterClipboardManager.copyFromClipBoard(text).then((result){
         print(result);
    });//支持调用.then方法
}

import 'packages:flutter_localization/flutter_localization.dart'

import 'package:permission_handler/permission_handler.dart';

Future requestPermission() async {
  // 申请权限
  Map<PermissionGroup, PermissionStatus> permissions =
      await PermissionHandler().requestPermissions([PermissionGroup.storage]);
  // 申请结果
  PermissionStatus permission =
      await PermissionHandler().checkPermissionStatus(PermissionGroup.storage);
  if (permission == PermissionStatus.granted) {
    Fluttertoast.showToast(msg: "权限申请通过");
  } else {
    Fluttertoast.showToast(msg: "权限申请被拒绝");
  }
}

version

import 'packages:flutter_svg/flutter_svg.dart'

//将svg格式的文件放在asset中，在yaml文件中引入资源
SvgPicture set = new SvgPicture.asset(
   "assets/set.svg",
    color: Colors.red
)//引入名为set的图标,宽度、颜色等样式可以自定义

import 'package:flutter_webview_plugin/flutter_webview_plugin.dart'

new MaterialApp(
      routes: {
        "/": (_) => new WebviewScaffold(
          url: "https://www.google.com",
          appBar: new AppBar(
            title: new Text("Widget webview"),
          ),
        ),
      },
    );

import 'package:connectivity/connectivity.dart';

var connectivityResult = await (Connectivity().checkConnectivity());
if (connectivityResult == ConnectivityResult.mobile) {
  // I am connected to a mobile network.
} else if (connectivityResult == ConnectivityResult.wifi) {
  // 连接到wifi
}

import 'package:flutter_map/flutter_map.dart';

import 'package:image_gallery_saver/image_gallery_saver.dart';

_save() async {
   var response = await Dio().get(
           "https://ss0.baidu.com/94o3dSag_xI4khGko9WTAnF6hhy/image/h%3D300/sign=a62e824376d98d1069d40a31113eb807/838ba61ea8d3fd1fc9c7b6853a4e251f94ca5f46.jpg",
           options: Options(responseType: ResponseType.bytes));
   final result = await ImageGallerySaver.saveImage(
           Uint8List.fromList(response.data),
           quality: 60,
           name: "hello");
   print(result);
  }

import 'package:keyboard_visibility/keyboard_visibility.dart';

@protected
void initState() {
  super.initState();

  KeyboardVisibilityNotification().addNewListener(
    onChange: (bool visible) {
      print(visible);
    },
  );
}

Image.asset('路径')//加载图片
future: DefaultAssetBundle.of(context).loadString("assets/sword.json")//加载json，加载后可以将json转化为dart进行显示

import 'package:flutter/services.dart' show rootBundle;

Future<String> loadAsset(async) {
    return await rootBundle.loadString('assets/sword.json')
}

AssetImage('icons/phone.png',package:'best_icons')

flutter:
     assets:
       - assets/

import 'package:audio_recorder/audio_recorder.dart';

// 检查权限
bool hasPermissions = await AudioRecorder.hasPermissions;

// 获取目前状态
bool isRecording = await AudioRecorder.isRecording;
// 开始录音
await AudioRecorder.start(path: _controller.text, audioOutputFormat: AudioOutputFormat.AAC);
// 结束录音
Recording recording = await AudioRecorder.stop();
print("Path : ${recording.path},  Format : ${recording.audioOutputFormat},  Duration : ${recording.duration},  Extension : ${recording.extension},");

import 'package:vibration/vibration.dart';

震动函数以ms为单位，
Vibration.vibrate(duration: 1000);//振动1s
Vibration.vibrate(pattern: [500, 1000, 500, 2000]);//振动0.5s，休息一秒，振动0.5秒，休息两秒
Vibration.vibrate(pattern: [500, 1000, 500, 2000], intensities: [1, 255]);//震动强度变化

dependencies:
  liquid_swipe: ^1.3.0

import 'package:liquid_swipe/Constants/Helpers.dart';
import 'package:liquid_swipe/liquid_swipe.dart';

dependencies:
  like_button: ^0.1.9

import 'package:like_button/like_button.dart';

dependencies:
  liquid_progress_indicator: ^0.3.2

import 'package:liquid_progress_indicator/liquid_progress_indicator.dart';

import 'package:sticky_headers/sticky_headers.dart';

ListView.builder(
    itemCount: 12,
    itemBuilder: (context, index) {
        return StickyHeader(
            header: Container( //header组件
                height: 50.0,
                color: Colors.blueGrey[700],
                padding: EdgeInsets.symmetric(horizontal: 16.0),
                alignment: Alignment.centerLeft,
                child: Text('Header #$index',
                    style: const TextStyle(color: Colors.white),
                ),
            ),
            content: Container(//内容组件
                child: Image.network(imgs[index], fit: BoxFit.cover,width: double.infinity, height: 200.0),
            ),
        );
    }
)

链接：https://juejin.im/post/5dce4a845188254c9479f0af

import 'package:flip_card/flip_card.dart';

FlipCard(
    direction: FlipDirection.VERTICAL, //基于X轴翻转
    front: Container(
        height: 200,
        width: 345,
        margin: EdgeInsets.all(10),
        color: Colors.teal,
        child: Center(
            child: Text("《遮天》",style:TextStyle(
                fontSize:40,
                color:Colors.white
            )),
        ),
    ),
    back: Container(
        height: 200,
        width: 345,
        margin: EdgeInsets.all(10),
        color: Colors.pink,
        padding: EdgeInsets.all(10),
        child: Text('....'
        ,style: TextStyle(
            color: Colors.white,
            height:2.0
        )),
    ),
),

链接：https://juejin.im/post/5dd4f84e5188254e0c036d5f

import 'package:scratcher/scratcher.dart';

Scratcher(
    brushSize: 30, //刷子大小（手指刮动的笔刷）
    threshold: 50, //完全刮开的阈值 百分比
    color: Colors.grey, //覆盖层的颜色
    onChange: (value) { //被刮动的回调 返回当前刮开区域百分比
        print("当前刮开比例: $value%");
    },
    onThreshold: () { //触发完全刮开的阈值回调
        print("已触发设置的全部刮开阈值");
    },
    child: Container( //覆盖层下的原本组件 一般是刮卡结果展示
        height: 150,
        width: 300,
        color: Colors.blue,
    ),
)

链接：https://juejin.im/post/5df5c48ae51d4558096d5887

import 'package:flutter_rating_bar/flutter_rating_bar.dart';

RatingBar(
    initialRating: rate1, //初始评分 double
    allowHalfRating: true,//允许0.5评分
    itemCount: 5,//评分组件个数
    itemPadding: EdgeInsets.symmetric(horizontal: 4.0),
    itemBuilder: (context, _) => Icon(
        Icons.star,
        color: Colors.amber,
    ),
    onRatingUpdate: (rating) {
        setState(() {
            this.rate1=rating;
        });
    },
)

链接：https://juejin.im/post/5dd1f9eae51d454014386435