在需要调用setState时在flutter中关闭简单对话框

import 'package:flutter/material.dart';

class MyDialog extends StatefulWidget {
  @override
  _MyDialogState createState() => _MyDialogState();
}

class _MyDialogState extends State<MyDialog> {
  bool showDialog = false;

  void openDialog() {
    setState(() {
      showDialog = true;
    });
  }

  void closeDialog() {
    Navigator.of(context).pop(); // 关闭对话框
    setState(() {
      showDialog = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Dialog Example'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            RaisedButton(
              child: Text('Open Dialog'),
              onPressed: openDialog,
            ),
            SizedBox(height: 20),
            showDialog
                ? SimpleDialog(
                    title: Text('Simple Dialog'),
                    children: <Widget>[
                      SimpleDialogOption(
                        onPressed: closeDialog,
                        child: Text('Close Dialog'),
                      ),
                    ],
                  )
                : Container(),
          ],
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: MyDialog(),
  ));
}