markdown Flutter点击两次退出App

Posted 2021-05-05

# 点击两次返回键，退出App

> 保证`Router`中的`home`已经设置了

## 解决方案
使用`WillPopScope`监听返回按键

在`Widget`中使用如下

```dart
import 'package:flutter/services.dart'; // 用来退出app
import 'dart:io'; // 用来退出app

...

Widget build(BuildContext context) {
    return WillPopScope(
        onWillPop: () async {
          // 点击返回键的操作
          if (lastPopTime == null ||
              DateTime.now().difference(lastPopTime) > Duration(seconds: 2)) {
            lastPopTime = DateTime.now();
            Toast.show("再按一次退出", context, duration: Toast.LENGTH_SHORT);

            return false;
          } else {
            // 退出app
            lastPopTime = DateTime.now();
            await SystemChannels.platform.invokeMethod('SystemNavigator.pop');
            exit(0);
            return true;
          }
        },
        child: yourContent )});

```