notes.md

#备注返回首页

##001-设置代理 由于某些不可抗力的原因，国内用户在访问国外的某些网站或搜索Flutter第三包时需要配置Flutter代理。在环境变量中配置如下:

export PUB_HOSTED_URL=https://pub.flutter-io.cn
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn

##002-获取第三方包时提示等待释放锁 当你的项目异常关闭，或者由于不可抗力的原因，在使用flutter packages get 命令更新第三方包时可能会出现Waiting for another flutter command to release the startup lock

其解决方案时删除flutter SDK目录下的lockfile文件即可。具体位置在

<fluttersdk>/bin/cache/lockfile

##003-设置屏幕方向 //横屏 SystemChrome.setPreferredOrientations( [DeviceOrientation.landscapeLeft, DeviceOrientation.landscapeRight]); //竖屏 SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp, DeviceOrientation.portraitDown]);

##004-获取尺寸

//屏幕宽高
var screenSize = MediaQuery.of(context).size
//状态栏高度
var statusHeight = MediaQuery.of(context).padding.top;

##005-判断设备类型

import 'dart:io';

Platform.isIOS
Platform.isAndroid
Platform.isMacOS
Platform.isWindows
Platform.isLinux
Platform.isFuchsia

##006-时间相关

var today = DateTime.now();
print('当前时间是：$today');

var date1 = today.millisecondsSinceEpoch;
print('当前时间戳：$date1');

var date2 = DateTime.fromMillisecondsSinceEpoch(date1);
print('时间戳转日期：$date2');

// 拼接成date
var dentistAppointment = new DateTime(2019, 6, 20, 17, 30,20);
print(dentistAppointment);

// 字符串转date
DateTime date3 = DateTime.parse("2019-06-20 15:32:41");
print(date3);
// DateTime转formatString 
// formatDate(DateTime ,[yyyy,'-',mm,'-',dd]);

// 时间比较
print(today.isBefore(date3));// 在之前
print(today.isAfter(date3)); // 在之后
print(date3.isAtSameMomentAs(date3));// 相同

print(date3.compareTo(today));// 大于返回1；等于返回0；小于返回-1。
// print(DateTime.now().toString());
// print(DateTime.now().toIso8601String());

// 时间增加
var fiftyDaysFromNow = today.add(new Duration(days: 5));
print('today加5天：$fiftyDaysFromNow');

// 时间减少
DateTime fiftyDaysAgo = today.subtract(new Duration(days: 5));
print('today减5天：$fiftyDaysAgo');

// 时间差 两个时间相差 小时数
print('比较两个时间 差 小时数：${fiftyDaysFromNow.difference(fiftyDaysAgo)}');

print('本地时区简码：${today.timeZoneName}');

print('返回UTC与本地时差 小时数：${today.timeZoneOffset}');

print('获取年月日：${today.year}');//month、day、hour、minute、second、millisecond、microsecond

print('星期：${today.weekday}');// 返回星期几

##007-剪切板

//赋值
ClipboardData willSetData = ClipboardData(text:"剪切板的文字");
Clipboard.setData(willSetData);

//取值
var clipboardData = await Clipboard.getData(Clipboard.kTextPlain);
if(clipboardData != null){
	var data = clipboardData.text;
}