Flutter 时间选择器，iOS样式
原版：https://github.com/wuzhendev/flutter-cupertino-date-picker
github： https://github.com/StephenNeverMore/FlutterTimePicker
在原版的基础上支持了年月日时分秒的选择样式
在项目的 pubspec.yaml 文件中添加依赖：
dependencies:
time_picker: ^0.0.1
执行 flutter packages get
import 'package:time_picker/time_picker.dart';
DatePicker.showDatePicker(context,
maxDateTime: DateTime.parse(MAX_DATETIME),
minDateTime: DateTime.parse(MIN_DATETIME),
pickerMode: mode,
dateFormat: format, onConfirm: (dateTime, list) {
print("onConfirm: $dateTime $list");
}, onClose: () {
print("onClose");
}, onCancel: () {
print("onCancel");
}, onChange: (dateTime, list) {
print("onChange: $dateTime $list");
});