Disable dropDown value in Flutter

policyDropdown = ['Platinum', 'Gold', 'Sr. Citizen'],

                child: Container(
                  height: 50.0,
                  child: ListTile(
                      title: Text('Policy Type'),
                      trailing: DropdownButtonHideUnderline(
                        child: DropdownButton(
                          value: policyDropdownData,
                          items: policyDropdown.map((String value) {
                            return DropdownMenuItem(
                              child: Text(value),
                              value: value,
                            );
                          }).toList(),
                          onChanged: (String? value) {
                            setState(() {
                              policyDropdownData = value.toString();
                              
                            });
                          },
                        ),

disable the first data of the policyDropdown... What can I do?

CodePudding user response：

You can use the enable property of the DropdownMenuItem and enable every other option than the first one of your policyDropdown list i.e."Platinum".

for example:

return DropdownMenuItem(
  value: value,
  child: Text(value),
  enabled: value != 'Platinum',
);

Additionally, If you want users to know that the option is disabled you can change the color of the text using the same logic.

return DropdownMenuItem(
  value: value,
  child: Text(
    value,
    style: TextStyle(
      color: value != 'Platinum'
          ? Colors.white
          : Colors.white60,
    ),
  ),
  enabled: value != 'Platinum',
);

CodePudding user response：

The answer given by @ibhavikmakwana is more than perfect. I just want to add the other method. You can achieve what you want by simply doing nothing in onChanged method. Like:

onChanged: (value) {}