按下应用程序后退按钮时如何确认应用程序退出 [英] How to confirm app exit when appbar back button is pressed

问题描述

我想在按下应用栏上的后退按钮时确认退出该应用.

I want to confirm exiting the app when the back button on the appbar is pressed.

 appBar: AppBar(
          leading: IconButton(
            icon: Icon(
              Icons.arrow_back_ios,
              color: Colors.white,
            ),
            onPressed: () {
              showDialog(
                context: context,
                builder: (context) {
                  return AlertDialog(
                    title: Text('Save and Exit?'),
                    content: Text('are you sure you want to save and exit?'),
                    actions: [
                      FlatButton(
                        onPressed: () => Navigator.pop(context, false),
                        child: Text('No'),
                      ),
                      FlatButton(
                        onPressed: () => Navigator.pop(context, true),
                        child: Text('Yes'),
                      ),
                    ],
                  );
                },
              );
              // Navigator.pop(context);
            },
          ),

我尝试了这个，但是没有用.我已经找到了一些有关使用 WillPopScope 按下系统后退按钮时如何执行操作的答案，但是在我的情况下，这些方法都不起作用.

I tried this but didn't work. I have found some answers on how to do it when the system back button is pressed using WillPopScope but none of them work in my case.

帮帮我

推荐答案

您可以使用Navigator.canPop(context)进行检查.它将返回true或false.在onPressed中可以检查它，如果为true，则可以执行Navigator.pop(context)，否则调用showDialog.

You can check it with Navigator.canPop(context) i guess. It will return true or false. in onPressed you can check it, if it's true you can do Navigator.pop(context) otherwise call showDialog.

有文档链接 https://api.flutter.dev/flutter/widgets/Navigator/canPop.html

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