Flutter Create a method including setState-CodePudding

I am trying to create a custom snackbar. It includes a "setState" executed after the snackbar dismisses. But the setStat function doesn't work (i.e., snackBarIsOn = false;). The snackbar pops up and dismisses after 2 seconds. It is also supposed to change "snackBarIsOn" to "true" but it doesn't happen. I tested it in the main code without the method. It works as it is supposed to. I am suspicious about the type of "actionAfterClosed".

Please help me.

customSnackBar(
     context: context,
     content: 'Enter a Title.',
     label: 'Close',
     textColor: Colors.white,
     snackBarAction: () {
               ScaffoldMessenger.of(context).hideCurrentSnackBar();
               setState(() {
                    snackBarIsOn = false;
               });
          },
     actionAfterClosed:
          setState(() {
               snackBarIsOn = false;
          })
     );



void customSnackBar(
    {required BuildContext context,
    required String content,
    required String label,
    required Color textColor,
    required VoidCallback snackBarAction,
    required **VoidCallback** actionAfterClosed}) {
  ScaffoldMessenger.of(context)
      .showSnackBar(SnackBar(
        content: Text(content),
        duration: const Duration(seconds: 2),
        action: SnackBarAction(
          label: label,
          textColor: textColor,
          onPressed: snackBarAction,
        ),
      ))
      .closed
      .then((_) =>
    actionAfterClosed
  );
}

CodePudding user response：

I believe this is the problem:

actionAfterClosed:
          setState(() {
               snackBarIsOn = false;
          })

Here, you are telling flutter to run setState, and then use whatever it returns as a callback, so it expects setState to return a function to call after the snackbar closes, instead of calling setState itself.

To fix this, you must use a function literal like you did for snackbarAction:

actionAfterClosed:
          () => setState(() {
               snackBarIsOn = false;
          })

The second problem I can find is here:

.closed
      .then((_) =>
    actionAfterClosed
  );

You forgot the parenthesis! this way the function isn't running!

.closed
      .then((_) =>
    actionAfterClosed()
  );