Flutter Navigator.of（context.pop（）；使整个屏幕消失，而不是弹出窗口

在我的

flatter

应用程序中，当用户按下按钮时，我想用两个按钮显示弹出窗口，我使用以下代码：

class ProfileScreen extends StatefulWidget {
  @override
  _ProfileScreenState createState() {
    return _ProfileScreenState();
  }
}

class _ProfileScreenState extends State<ProfileScreen> {

@override
Widget build(BuildContext context) {
return Scaffold(
    body: SingleChildScrollView(
        padding: EdgeInsets.all(16),
        child: ConstrainedBox(
            constraints: BoxConstraints(maxWidth: 400),
            child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.center,
                children: [
                  ...[
Padding(
    padding: const EdgeInsets.symmetric(vertical: 16.0),
    child: ElevatedButton(
      onPressed: () {
        showAlertDialog(context);
      },
    child: Text('Remove account'),
    ),
    ),

它工作正常，弹出窗口显示正确，但当我单击“取消”时，弹出窗口保持在前面，但其下方的屏幕消失（并保持黑色）。为什么会这样？我怎样才能修好它呢？谢谢

Navigator.of（上下文，rootNavigator:true）.pop（）

这也可能有帮助：

showAlertDialog(BuildContext context) {
    // set up the buttons
    Widget cancelButton = FlatButton(
      child: Text("Cancel"),
      onPressed:  () {

        Navigator.of(context).pop();
      },
    );
    Widget continueButton = FlatButton(
      child: Text("Continue"),
      onPressed:  () {},
    );
    // set up the AlertDialog
    AlertDialog alert = AlertDialog(
      title: Text("AlertDialog"),
      content: Text("Would you like to continue learning how to use Flutter alerts?"),
      actions: [
        cancelButton,
        continueButton,
      ],
    );
    // show the dialog
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return alert;
      },
    );
  }