问题描述
我正在尝试获取 Wifi AP 详细信息。我正在使用以下代码
private val TAG = "[MainActivity]"
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val receiver = object : broadcastReceiver() {
override fun onReceive(context: Context?,intent: Intent?) {
if(WifiManager.NETWORK_STATE_CHANGED_ACTION == intent?.action){
val networkInfo = intent.getParcelableExtra<NetworkInfo>(WifiManager.EXTRA_NETWORK_INFO)
if(ConnectivityManager.TYPE_WIFI == networkInfo.type){
val wifiManager = applicationContext.getSystemService(Context.WIFI_SERVICE) as WifiManager
val info = wifiManager.connectionInfo
Log.d(TAG,"info = $info")
}
}
}
}
val intentFilter = IntentFilter()
intentFilter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION)
applicationContext.registerReceiver(receiver,intentFilter)
}
NetworkInfo 和 ConnectivityManager.TYPE_WIFI 显示已弃用。我也将 SSID 设为 null。
info = SSID:,BSSID: 02:00:00:00:00:00,MAC: 02:00:00:00:00:00,Supplicant state: COMPLETED
我使用的权限：
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
完成上述任务的最佳方法是什么？
解决方法
您必须拥有位置权限才能获取 WiFi AC 详细信息（请参阅 Location Requirements for WiFi APIs）。
在清单中声明 ACCESS_FINE_LOCATION 不足以获取 WiFi 信息 - 用户必须授予您该权限（通过在运行时向用户请求权限或用户在应用程序中手动打开权限）信息）。
此外，在 Android 10 中，谷歌添加了 enforcement that prevents you from getting the permission in the background，因此请记住，仅当您的应用处于前台时，仅请求 ACCESS_FINE_LOCATION 才允许您获取 WiFi AC 详细信息。
要在后台获取 WiFi AC 详细信息，您必须声明（并被授予）ACCESS_BACKGROUND_LOCATION 以及常规位置权限。
@Shlomi 答案的补充，
这是在运行时从用户那里获取权限的示例
操作前先检查
if (!checkPermissions()) {
// App does not have permissions,ask for permissions.
requestPermissions()
} else {
// App has permissions
// Perform your operations here......
}
检查和询问权限的代码
科特林
/**
* Return the current state of the permissions needed.
*/
private fun checkPermissions(): Boolean {
val permissionState = ActivityCompat.checkSelfPermission(
requireContext(),Manifest.permission.ACCESS_FINE_LOCATION
)
return permissionState == PackageManager.PERMISSION_GRANTED
}
private fun requestPermissions() {
val shouldProvideRationale = ActivityCompat.shouldShowRequestPermissionRationale(
requireActivity(),Manifest.permission.ACCESS_FINE_LOCATION
)
// Provide an additional rationale to the user. This would happen if the user denied the
// request previously,but didn't check the "Don't ask again" checkbox.
if (shouldProvideRationale) {
Log.i(
TAG,"Displaying permission rationale to provide additional context."
)
Snackbar.make(
binding.wifiConnectionFragment,"Location permission is needed for core functionality",Snackbar.LENGTH_INDEFINITE
)
.setAction("OK") { // Request permission
ActivityCompat.requestPermissions(
requireActivity(),arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),REQUEST_PERMISSIONS_REQUEST_CODE
)
}
.show()
} else {
Log.i(TAG,"Requesting permission")
// Request permission. It's possible this can be auto answered if device policy
// sets the permission in a given state or the user denied the permission
// previously and checked "Never ask again".
ActivityCompat.requestPermissions(
requireActivity(),REQUEST_PERMISSIONS_REQUEST_CODE
)
}
}
override fun onRequestPermissionsResult(
requestCode: Int,permissions: Array<out String>,grantResults: IntArray
) {
super.onRequestPermissionsResult(requestCode,permissions,grantResults)
if (requestCode == REQUEST_PERMISSIONS_REQUEST_CODE) {
if (grantResults.isEmpty()) {
} else if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission Granted
// Perform your operations
} else {
// Permission denied.
// Notify the user via a SnackBar that they have rejected a core permission for the
// app,which makes the Activity useless. In a real app,core permissions would
// typically be best requested during a welcome-screen flow.
// Additionally,it is important to remember that a permission might have been
// rejected without asking the user for permission (device policy or "Never ask
// again" prompts). Therefore,a user interface affordance is typically implemented
// when permissions are denied. Otherwise,your app could appear unresponsive to
// touches or interactions which have required permissions.
Snackbar.make(
binding.wifiConnectionFragment,"Permission was denied,but is needed for core functionality.",Snackbar.LENGTH_INDEFINITE
)
.setAction(
"Settings",View.OnClickListener { // Build intent that displays the App settings screen.
val intent = Intent()
intent.action = Settings.ACTION_APPLICATION_DETAILS_SETTINGS
val uri = Uri.fromParts(
"package",BuildConfig.APPLICATION_ID,null
)
intent.data = uri
intent.flags = Intent.FLAG_ACTIVITY_NEW_TASK
startActivity(intent)
})
.show()
}
}
}