Failed assertion: line 4950 pos 12: '!_debugLocked': is not true using showtimepicker widget

Question

I am building to do app and I want to add date in the to do list using showtimepicker widget and I when I did it, the widget appear to me but whenever I press ok or cancel it show me the error above '!_debugLocked': is not true.'

TextFormField(
  onTap: 
() {showTimePicker(context: context, initialTime: TimeOfDay.now());}),

  controller: datecontroller,
  keyboardType: TextInputType.text
,
  onFieldSubmitted: (String value) {
    print(value);
  },
  validator: (String? value) {
    if (value!.isEmpty) {
      return 'date can\'t be empty';
    }
    return null;
  },
);

I tried to do a function outside the textfromfield but it didn't work because of the error This expression has a type of 'void' so its value can't be used.