如何检查警报对话框是否在颤振中打开

Question

I am working on my flutter application and I want to check whether the alert dialog is open or not on the screen . Can anyone tell me how to do that, basically I want to do some stuff just before and after alert dialog opens and closes.

Answer 1

First thing is you will be showing dialog yourself. So, you can use a bool value to track it.

Like this.

bool _isDialogShowing = false;

void _showDialog() {
  _isDialogShowing = true; // set it `true` since dialog is being displayed
  showDialog(
    context: context,
    builder: (context) {
      return AlertDialog(
        title: Text("Title"),
        actions: <Widget>[
          FlatButton(
            child: Text("CANCEL"),
            onPressed: () {
              _isDialogShowing = false; // set it `false` since dialog is closed
              Navigator.of(context).pop();
            },
          )
        ],
      );
    },
  );
}

To listen for back button, you can wrap your root widget in WillPopScope and handle things in onWillPop() accordingly.

Answer 2

try this !!!

Future _dialog;

_checkAndShowDialog() async {

    if (_dialog == null) {
      _dialog = showMyDialog();
      await _dialog;
      _dialog = null;
    } else {
     //do nothing
    }

}

//dialog should return future
Future showMyDialog() {
    return showDialog(
        context: _context,
        child: Container(child: Text("I am dialog"),) );
  }

Answer 3

I had the same problem. Maybe my solution would do any better for someone:

_isOpen = true;
showDialog(
    context: context,
    child: AlertDialog(
      title: Text("Some title!"),
      content: Text("Some content!"),
    )).then((_) => _isOpen = false);

The then will run when the alert closes.

Answer 4

In your case its better to use a full screen dialog then u can create frosted glass effect and in center u can add alert box like container and decorate it. To make modal barier like effect wrap outter frosted glass container with inkWell or gesture detector and on tap pop the screen

Answer 5

You can assign the alert dialog to a variable and use the build method to populate it. Later check the variable to know whether the dialog is being shown or not.

Answer 6

"so I want to add a frosted glass background behind my alert , so what i want to do is before pushing alert dialog i want to change my screen to frosted glass bg and then after poping up alert i want to remove that bg using setState .That's why I want to listen to the alert dialog. Hope this all makes sense to you! Thanks !"

This is what you responded as the purpose of your dialog.

You can await a dialog like this:

<do setup code here>

await showDialog(...);

<do final code here>

Regardless of how you show the dialog I don't see a flaw on this. If you don't have this on an async function you can always call .then and do stuff there:

<do setup code here>

showDialog(...).then((_) => <do final code here>);

Answer 7

you can use this method:

_isThereCurrentDialogShowing(BuildContext context) =>
  ModalRoute.of(context)?.isCurrent != true;