how to modify date_picker.dart to remove ok and cancel button - datepicker

Question

i am building a mobile app that allows the user to pick the date from a date picker,
when opening the picker screen it overflows from the button
i searched the problem and find the same problem here
https://github.com/flutter/flutter/issues/19744
it is mentioned in the solution that he modified the file " date_picker.dart "
how can i find this file and how to apply these changes
the code i used :
DateTime TodayDate = new DateTime.now();Future<Null> selectDate(BuildContext context) async{
final DateTime Picker = await showDatePicker(
context: context,
initialDate: TodayDate,
firstDate: TodayDate,
lastDate: new DateTime(2021),
);
if (Picker != null && Picker != TodayDate){
print('${TodayDate.toString()} تاريخ الرحلة : ');
setState(() {
TodayDate = Picker;
});
}}
inside the widget build
new RaisedButton(onPressed:(){selectDate(context);},
color: Colors.lightGreen,
textColor: Colors.grey[200],
child: const Text('اختيا تاريخ الرحلة'),
shape: new RoundedRectangleBorder(borderRadius: new BorderRadius.circular(30.0)),
),

Answer 1

Don't.
Editing the file directly is going to break (ie not have your customization) if anyone else tries to run this code on their own machine.
You'll break your own code if you ever update Flutter.
Look into overriding the showDatePicker build() method. Copying its content and adding your customization would be much preferable to actually editing the file. Although - even this still seems very sketchy though. Think about a year down the road when Flutter decides to change the implementation of showDatePicker.build(). Unless you are committed to maintaining this code with every Flutter update, you may be out of luck.
The ideal solution is to request a feature addition, or to do it yourself and try to get it integrated. Obviously if you need this functionality asap that isn't going to help you much.
Edit: There appears to be workaround that involves using a SingleChildScrollView to avoid the overflow - see https://github.com/flutter/flutter/issues/19744#issuecomment-493873347
DateTime dateTime = await showDatePicker(
context: context,
initialDate: DateTime(2000),
firstDate: DateTime(1950),
lastDate: DateTime(DateTime.now().year + 1),
builder: (context, child) {
return SingleChildScrollView(
child: Theme(
child: child,
data: ThemeData.light(),
),
);
});

Answer 2

In Android Studio, select showDatePicker, then press CTRL + F
The file date_picker.dart will open in a new tab. Around line 960 in the file is the ButtonBar you are looking for. Now when you try to edit it, a warning will pop up:
Just press OK and edit as you like. Beware that the changes might be overwritten when you run flutter upgrade. It might be better to copy the whole file into your project to create your own version of the date picker.