How to add onChanged to DropDownlist? crash happening in dropdown

[neenabastin123]

I/flutter ( 5339): 'package:flutter/src/material/dropdown.dart': Failed assertion: line 608 pos 15: 'items == null ||
I/flutter ( 5339): items.isEmpty || value == null || items.where((DropdownMenuItem item) => item.value ==
I/flutter ( 5339): value).length == 1': is not true.

[danvick]

Hi @neenabastin123 / @dhsont,
This assertion is not part of the package, rather in Flutter. This shows that your initial value for the Dropdown is not part of the list of options you've provided as DropdownMenuItems.

Feel free to reopen this issue if you feel that this issue has been wrongly closed.