Flutter：弹出 2 个警报对话框时应用程序崩溃

Posted 2023-02-23

【中文标题】Flutter：弹出 2 个警报对话框时应用程序崩溃

【英文标题】：Flutter: app crashes when 2 alert dialogs are pops

【发布时间】：2021-07-24 12:14:00

【问题描述】：

如果快速点击两张卡，会出现黑屏，需要重启应用

Flutter 2.0.5 • 通道稳定 • https://github.com/flutter/flutter.git 框架 • 修订版 adc687823a（2 周前） • 2021-04-16 09:40:20 -0700 引擎 • 修订版 b09f014e96 工具• Dart 2.12.3

脚手架

class HomePage extends StatelessWidget 
  @override
  Widget build(BuildContext context) 
    return Scaffold(
        body: Container(
      child: Column(
        children: [
          GestureDetector(
            child: Container(
                child: GFCard('The quick brown fox jumps over the lazy dog')),
            onTap: Alerts.correct(context),
          ),
          GestureDetector(
            child: GFCard('The quick brown fox jumps over the lazy dog'),
            onTap: Alerts.wrong(context),
          ),
        ],
      ),
    ));
  

提醒

import 'package:flutter/material.dart';
import 'dart:async';

class Alerts 
  static correct(BuildContext context) 
    return () => _alert(context,
        backgroundColor: Color(0xFF25C047), message: 'Correct ????');
  

  static wrong(BuildContext context) 
    return () => _alert(context,
        backgroundColor: Color(0xFFC22121), message: 'Wrong :(');
  

   static _alert(BuildContext context, Color backgroundColor, String message) 
    return showDialog(
      barrierColor: Colors.transparent,
      context: context,
      builder: (BuildContext context) 
        Timer(Duration(milliseconds: 500), () => Navigator.of(context).pop());
        return AlertDialog(
          insetPadding: EdgeInsets.all(35),
          shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.all(Radius.circular(16))),
          content: Text(
            message,
            style: TextStyle(
              color: Colors.white,
              fontSize: 24,
            ),
            textAlign: TextAlign.center,
          ),
          elevation: 24,
          backgroundColor: backgroundColor,
          // shape: RoundedRectangleBorder(),
        );
      ,
    );
  

错误

E/flutter ( 5535): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: Looking up a deactivated widget's ancestor is unsafe.
E/flutter ( 5535): At this point the state of the widget's element tree is no longer stable.
E/flutter ( 5535): To safely refer to a widget's ancestor in its dispose() method, save a reference to the ancestor by calling dependOnInheritedWidgetOfExactType() in the widget's didChangeDependencies() method.```

【参考方案1】：

要解决这个问题，您应该在 showDialog() 中设置 barrierDismissible: false