Update alphabet sidebar while scrolling about country-list-pick HOT 2 CLOSED

CountryListPick(
    appBar: AppBar(
          // create your own appBar, default appBar(blue, centerTitle)
       ),
        pickerBuilder: (context, CountryCode countryCode) {
              // create your own picker, the default is countryflag, country name, keyboard_arrow_down
              return Row(
                children: [
                  Image.asset(
                    countryCode.flagUri,
                    package: 'country_list_pick', // do not forget this 
                  ),
                  Text(countryCode.code),
                  Text(countryCode.dialCode),
                ],
              );
            },
            theme: CountryTheme(
              // create your own theme customization, check CountryTheme class for more details
              isShowFlag: true,
              isShowTitle: true,
              isShowCode: true,
              isDownIcon: true,
              showEnglishName: true,
            ),
            initialSelection: '+62',
            onChanged: (CountryCode code) {
              print(code.name);
              print(code.code);
              print(code.dialCode);
              print(code.flagUri);
            },         
     ),