var status = await Permission.notification.status;
print(status);

// 申請(qǐng)通知權(quán)限：
await Permission.notification.request();
// 同時(shí)申請(qǐng)多個(gè)權(quán)限：
await [
  Permission.notification,
  Permission.photos,
].request();

openAppSettings();

import 'dart:io';
import 'package:flutter/cupertino.dart';
import 'package:flutter/services.dart';
import 'package:permission_handler/permission_handler.dart';
/// 權(quán)限檢查及請(qǐng)求
/// 
/// 外部可通過(guò)此方法來(lái)進(jìn)行權(quán)限的檢查和請(qǐng)求，將自動(dòng)跳轉(zhuǎn)到`PermissionRequestPage`頁(yè)面。
/// 
/// 傳入 `Permission` 以及對(duì)應(yīng)的權(quán)限名稱 `permissionTypeStr`，如果有權(quán)限則返回 `Future true`
/// 
/// `isRequiredPermission` 如果為 `true`,則 "取消" 按鈕將執(zhí)行 "退出app" 的操作
Future<bool> permissionCheckAndRequest(
    BuildContext context,
    Permission permission,
    String permissionTypeStr,{
    bool isRequiredPermission = false
    }) async {
  if (!await permission.status.isGranted) {
    await Navigator.of(context).push(
          PageRouteBuilder(
            opaque: false,
            pageBuilder: ((context, animation, secondaryAnimation) {
              return PermissionRequestPage(permission, permissionTypeStr, isRequiredPermission: isRequiredPermission);
            }))
          ); 
  } else {
    return true;
  }
  return false;
}
class PermissionRequestPage extends StatefulWidget {
  const PermissionRequestPage(this.permission, this.permissionTypeStr,{super.key, this.isRequiredPermission = false});
  final Permission permission;
  final String permissionTypeStr;
  final bool isRequiredPermission;
  @override
  State<PermissionRequestPage> createState() => _PermissionRequestPageState();
}
class _PermissionRequestPageState extends State<PermissionRequestPage> with WidgetsBindingObserver {
  bool _isGoSetting = false;
  late final List<String> msgList;
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
    msgList = [
      "${widget.permissionTypeStr}功能需要獲取您設(shè)備的${widget.permissionTypeStr}權(quán)限，否則可能無(wú)法正常工作。\n是否申請(qǐng)${widget.permissionTypeStr}權(quán)限？",
      "${widget.permissionTypeStr}權(quán)限不全，是否重新申請(qǐng)權(quán)限？",
      "沒(méi)有${widget.permissionTypeStr}權(quán)限，您可以手動(dòng)開(kāi)啟權(quán)限",
      widget.isRequiredPermission ? "退出應(yīng)用" : "取消"
    ];
    checkPermission(widget.permission);
  }
  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);
    // 監(jiān)聽(tīng) app 從后臺(tái)切回前臺(tái)
    if (state == AppLifecycleState.resumed && _isGoSetting) {
      checkPermission(widget.permission);
    }
  }
  /// 校驗(yàn)權(quán)限
  void checkPermission(Permission permission) async {
    final status = await permission.status;
    if (status.isGranted) {
      _popPage();
      return;
    }
    // 還未申請(qǐng)權(quán)限或之前拒絕了權(quán)限(在 iOS 上為首次申請(qǐng)權(quán)限，拒絕后將變?yōu)?`永久拒絕權(quán)限`)
    if (status.isDenied) {
      showAlert(permission, msgList[0], msgList[3], _isGoSetting ? "前往應(yīng)用中心" : "確定");
    }
    // 權(quán)限已被永久拒絕
    if (status.isPermanentlyDenied) {
      _isGoSetting = true;
      showAlert(permission, msgList[2], msgList[3], _isGoSetting ? "前往應(yīng)用中心" : "確定");
    }
    // 擁有部分權(quán)限
    if (status.isLimited) {
      if (Platform.isIOS || Platform.isMacOS) _isGoSetting = true;
      showAlert(permission, msgList[1], msgList[3], _isGoSetting ? "前往應(yīng)用中心" : "確定");
    }
    // 擁有部分權(quán)限(僅限 iOS)
    if (status.isRestricted) {
      if (Platform.isIOS || Platform.isMacOS) _isGoSetting = true;
      showAlert(permission, msgList[1], msgList[3], _isGoSetting ? "前往應(yīng)用中心" : "確定");
    }
  }
  void showAlert(Permission permission, String message, String cancelMsg, String confirmMsg) {
    showCupertinoDialog(
      context: context, 
      builder: (context) {
        return CupertinoAlertDialog(
          title: const Text("溫馨提示"),
          content: Text(message),
          actions: [
            CupertinoDialogAction(
              child: Text(cancelMsg),
              onPressed: () {
                widget.isRequiredPermission ? _quitApp() : _popDialogAndPage(context);
              }),
            CupertinoDialogAction(
              child: Text(confirmMsg),
              onPressed: () {
                if (_isGoSetting) {
                  openAppSettings();
                  _isGoSetting = true;
                } else {
                  requestPermisson(permission);
                }
                _popDialog(context);
              })
          ],
        );
      }
    );
  }
  /// 申請(qǐng)權(quán)限
  void requestPermisson(Permission permission) async {
    // 申請(qǐng)權(quán)限
    await permission.request();
    // 再次校驗(yàn)
    checkPermission(permission);
  }
  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }
  @override
  Widget build(BuildContext context) {
    return Container();
  }
  /// 退出應(yīng)用程序
  void _quitApp() {
    SystemChannels.platform.invokeMethod("SystemNavigator.pop");
  }
  /// 關(guān)閉整個(gè)權(quán)限申請(qǐng)頁(yè)面
  void _popDialogAndPage(BuildContext dialogContext) {
    _popDialog(dialogContext);
    _popPage();
  }
  /// 關(guān)閉彈窗
  void _popDialog(BuildContext dialogContext) {
    Navigator.of(dialogContext).pop();
  }
  /// 關(guān)閉透明頁(yè)面
  void _popPage() {
    Navigator.of(context).pop();
  }
}

<uses-permission android:name="android.permission.CAMERA" />

// 導(dǎo)入封裝好的文件
import 'package:xxxx/permission_request.dart';
// ...其它代碼
ElevatedButton(
  onPressed: () async {
    // 調(diào)用封裝好的權(quán)限檢查和請(qǐng)求方法
    bool result = await permissionCheckAndRequest(
                          context, 
                          Permission.notification，
                           "通知"
                        );
    if (result) print("已擁有該權(quán)限");
  },
  child: const Text("權(quán)限檢查")
)