我正在我的应用程序中处理后退按钮,但我在颤动中遇到了这个问题\n非常感谢高级\我之前使用此功能执行过此操作,但现在它不起作用\我认为是因为空安全\n对不起我英语不好\n截图
\n这是我的扑动医生
\nDoctor summary (to see all details, run flutter doctor -v):\n[\xe2\x88\x9a] Flutter (Channel stable, 2.2.3, on Microsoft Windows [Version 10.0.19043.1110], locale en-US)\n[\xe2\x88\x9a] Android toolchain - develop for Android devices (Android SDK version 30.0.3)\n[\xe2\x88\x9a] Chrome - develop for the web\n[\xe2\x88\x9a] Android Studio (version 4.1.0)\n[\xe2\x88\x9a] VS Code (version 1.58.2)\n[\xe2\x88\x9a] Connected device (3 available)\n\n\xe2\x80\xa2 No issues found!\nRun Code Online (Sandbox Code Playgroud)\n这是我的构建方法和 Future 函数
\nFuture<bool> _onBackPress() {\n return showDialog(\n context: context,\n builder: (BuildContext context) {\n return AlertDialog(\n content: Text(\'Exit From …Run Code Online (Sandbox Code Playgroud)