Dart学习字符串之左右补全padLeft and padRight

Flutter日常开发中封装日期组件时发现返回值需要补全字符串日期

import 'package:flutter/material.dart';
import 'package:x_pms_cloud_client/global_instance/global_instance.dart';

Future showDatePickerTN(context)async{
  var date;
  await showDatePicker(
      context: context,
      locale: Locale('zh'),
      initialDate: DateTime.parse(GlobalInstance.instance.getHotelDate),
      firstDate: new DateTime(2000),
      lastDate: new DateTime(2100),
  ).then((value) => date = "${value!.year.toString()}-${value.month.toString().padLeft(2,'0')}-${value.day.toString().padLeft(2,'0')}"
);
  return date;
}

1. padLeft(int lenght,'字符串') 字符的长度小于width时用 ‘字符串’ 补全
2. padRight(int lenght,'字符串') 字符的长度小于width时用 ‘字符串’ 补全

注释：以下内容纯属小白理解，如有错误之处欢迎指正