在项目中集成了百度定位插件（flutter_bmflocation），但是在申请定位权限时一直不弹出申请框，打印请求结果一直返回 PermissionStatus.permanentlyDenied。

正常情况，在执行 requestPermission() 方法时，会弹出下面对话框。

IMG_6551.jpg

我检查了 iOS 工程下的 Info.plist 文件，发现申请定位权限的描述已经正确填写。

<key>NSLocationWhenInUseUsageDescription</key>
<string>需要访问位置。</string>

不断重复查看各类文档，都没找到解决方案。

后来分析百度定位插件的源码，发现该插件依赖 permission_handler 插件。

该插件提到，使用时需要按需修改 Podfile，根据需要的权限按情况修改（或添加）以下内容。

根据文档提示，添加相关内容后，问题解决。

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      ... # Here are some configurations automatically generated by flutter

      # You can enable the permissions needed here. For example to enable camera
      # permission, just remove the `#` character in front so it looks like this:
      #
      # ## dart: PermissionGroup.camera
      # 'PERMISSION_CAMERA=1'
      #
      #  Preprocessor definitions can be found in: https://github.com/Baseflow/flutter-permission-handler/blob/master/permission_handler/ios/Classes/PermissionHandlerEnums.h
      config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= [
        '$(inherited)',

        ## dart: PermissionGroup.calendar
        # 'PERMISSION_EVENTS=1',

        ## dart: PermissionGroup.reminders
        # 'PERMISSION_REMINDERS=1',

        ## dart: PermissionGroup.contacts
        # 'PERMISSION_CONTACTS=1',

        ## dart: PermissionGroup.camera
        # 'PERMISSION_CAMERA=1',

        ## dart: PermissionGroup.microphone
        # 'PERMISSION_MICROPHONE=1',

        ## dart: PermissionGroup.speech
        # 'PERMISSION_SPEECH_RECOGNIZER=1',

        ## dart: PermissionGroup.photos
        # 'PERMISSION_PHOTOS=1',

        ## dart: [PermissionGroup.location, PermissionGroup.locationAlways, PermissionGroup.locationWhenInUse]
        # 'PERMISSION_LOCATION=1',

        ## dart: PermissionGroup.notification
        # 'PERMISSION_NOTIFICATIONS=1',

        ## dart: PermissionGroup.mediaLibrary
        # 'PERMISSION_MEDIA_LIBRARY=1',

        ## dart: PermissionGroup.sensors
        # 'PERMISSION_SENSORS=1',   

        ## dart: PermissionGroup.bluetooth
        # 'PERMISSION_BLUETOOTH=1',

        ## dart: PermissionGroup.appTrackingTransparency
        # 'PERMISSION_APP_TRACKING_TRANSPARENCY=1',

        ## dart: PermissionGroup.criticalAlerts
        # 'PERMISSION_CRITICAL_ALERTS=1'
      ]

    end
  end
end