flutter 完美处理iOS Android两端蓝牙权限，解决Android12蓝牙扫描崩溃

前言

最近在做一个配置工具，给Zigbee网关配置网络的工具，其中有一个环节，是用蓝牙配置，过程遇到权限各种坑，故有此篇文章，其中我们使用了第三方库permission_handler,而且permission_handler版本要大于8.2.0才行。

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Android端

第一步：工程名称/android/app/src/main/AndroidManifest.xml,下添加以下权限

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代码如下：

在Android12之前的版本,只需要授权位置权限，下面这些都是PermissionStatus.granted

    var isLocationGranted = await Permission.locationWhenInUse.request();
    print('checkBlePermissions, isLocationGranted=$isLocationGranted');


    var isBleGranted = await Permission.bluetooth.request();
    print('checkBlePermissions, isBleGranted=$isBleGranted');

    var isBleScanGranted = await Permission.bluetoothScan.request();
    print('checkBlePermissions, isBleScanGranted=$isBleScanGranted');
    //
    var isBleConnectGranted = await Permission.bluetoothConnect.request();
    print('checkBlePermissions, isBleConnectGranted=$isBleConnectGranted');
    //
    var isBleAdvertiseGranted = await Permission.bluetoothAdvertise.request();
    print('checkBlePermissions, isBleAdvertiseGranted=$isBleAdvertiseGranted');

在>=Android12的版本,除了需要授权“位置权限”，还需要授权“使用附近的设备权限” ，下面这些才会都是PermissionStatus.granted，蓝牙才能正常使用起来

    var isBleScanGranted = await Permission.bluetoothScan.request();
    print('checkBlePermissions, isBleScanGranted=$isBleScanGranted');
    //
    var isBleConnectGranted = await Permission.bluetoothConnect.request();
    print('checkBlePermissions, isBleConnectGranted=$isBleConnectGranted');
    //
    var isBleAdvertiseGranted = await Permission.bluetoothAdvertise.request();
    print('checkBlePermissions, isBleAdvertiseGranted=$isBleAdvertiseGranted');

需要注意的是：在>=Android12的版本, var isBleGranted = await Permission.bluetooth.request();默认为PermissionStatus.denied，应该是因为使用了上面3个权限代替了

第二步，动态申请权限最终代码

其中投机取巧了一下

  Future requestBlePermissions() async {
    location.Location _location = new location.Location();
    bool _serviceEnabled;

    _serviceEnabled = await _location.serviceEnabled();
    if (!_serviceEnabled) {
      _serviceEnabled = await _location.requestService();
      if (!_serviceEnabled) {
        return false;
      }
    }
    var isLocationGranted = await Permission.locationWhenInUse.request();
    print('checkBlePermissions, isLocationGranted=$isLocationGranted');


    var isBleGranted = await Permission.bluetooth.request();
    print('checkBlePermissions, isBleGranted=$isBleGranted');

    var isBleScanGranted = await Permission.bluetoothScan.request();
    print('checkBlePermissions, isBleScanGranted=$isBleScanGranted');
    //
    var isBleConnectGranted = await Permission.bluetoothConnect.request();
    print('checkBlePermissions, isBleConnectGranted=$isBleConnectGranted');
    //
    var isBleAdvertiseGranted = await Permission.bluetoothAdvertise.request();
    print('checkBlePermissions, isBleAdvertiseGranted=$isBleAdvertiseGranted');

    if(Platform.isIOS) {
      return isBleGranted == PermissionStatus.granted;

    }else {
      return isLocationGranted == PermissionStatus.granted &&
           // isBleGranted == PermissionStatus.granted  &&
          isBleScanGranted == PermissionStatus.granted &&
          isBleConnectGranted == PermissionStatus.granted &&
          isBleAdvertiseGranted == PermissionStatus.granted;
    }
  }

iOS端

第一步：info.plist文件申请

image.png

第二步：增加后台模式权限

image.png

如下图所示，选中

image.png

第三步：Podfile文件里面添加代码

image.png

代码如下：

    target.build_configurations.each do |config|
      config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] ||= [
        '$(inherited)',
        # dart: [PermissionGroup. location, PermissionGroup. locationAlways, PermissionGroup. locationWhenInUse]
        'PERMISSION_LOCATION=1',
        ## dart: PermissionGroup.bluetooth
        'PERMISSION_BLUETOOTH=1',
      ]
    end

第四步：Podfile文件里面添加代码后，需要重新pod install，安装一下,才会产生效果

第五步：在代码里面调用蓝牙权限

image.png

  Future requestBlePermissions() async {
    location.Location _location = new location.Location();
    bool _serviceEnabled;

    _serviceEnabled = await _location.serviceEnabled();
    if (!_serviceEnabled) {
      _serviceEnabled = await _location.requestService();
      if (!_serviceEnabled) {
        return false;
      }
    }
    var isLocationGranted = await Permission.locationWhenInUse.request();
    print('checkBlePermissions, isLocationGranted=$isLocationGranted');


    var isBleGranted = await Permission.bluetooth.request();
    print('checkBlePermissions, isBleGranted=$isBleGranted');

    var isBleScanGranted = await Permission.bluetoothScan.request();
    print('checkBlePermissions, isBleScanGranted=$isBleScanGranted');
    //
    var isBleConnectGranted = await Permission.bluetoothConnect.request();
    print('checkBlePermissions, isBleConnectGranted=$isBleConnectGranted');
    //
    var isBleAdvertiseGranted = await Permission.bluetoothAdvertise.request();
    print('checkBlePermissions, isBleAdvertiseGranted=$isBleAdvertiseGranted');

    if(Platform.isIOS) {
      return isBleGranted == PermissionStatus.granted;

    }else {
      return isLocationGranted == PermissionStatus.granted &&
           // isBleGranted == PermissionStatus.granted  &&
          isBleScanGranted == PermissionStatus.granted &&
          isBleConnectGranted == PermissionStatus.granted &&
          isBleAdvertiseGranted == PermissionStatus.granted;
    }
  }

最终效果

两端都可以弹框出来申请权限，授受后，可以正常使用起来，还适配了Android12，
如果没有适配Android12的代码，一开始蓝牙扫描，app就会崩溃

结尾

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