Android 扫描WIFI权限详解

权限

上篇文章 Android 获取IP和UA中提及了获取WIFI的IP地址，本篇文章介绍下如何扫描WIFI。

官方文档

根据官方文档描述，扫描WIFI需要申请相关权限，如下：

Android 13以上

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
   <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
   <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
   <!--在Android13以上，当usesPermissionFlags设置为neverForLocation时，无需再申请ACCESS_FINE_LOCATION权限-->
   <uses-permission
       android:name="android.permission.NEARBY_WIFI_DEVICES"
       android:usesPermissionFlags="neverForLocation" />
</manifest>

Android 13以下

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
   <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
   <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
   <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
</manifest>

需要注意，在实际测试中，Android 13以上的设备仍然需要申请android.permission.ACCESS_FINE_LOCATION才能扫描到WIFI，测试设备为小米13。

注册广播监听扫描状态

通过注册广播监听WIFI扫描是否完成，代码如下：

class WIFIExampleActivity : AppCompatActivity() {
   private val scanResultReceiver = object : BroadcastReceiver() {
       override fun onReceive(context: Context?, intent: Intent?) {
           if (intent?.getBooleanExtra(WifiManager.EXTRA_RESULTS_UPDATED, false) == true) {
               // 扫描完成
           }
       }
   }
   override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)
       // 注册广播
       registerReceiver(scanResultReceiver, IntentFilter().apply {
           addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)
       })
   }
   override fun onDestroy() {
       super.onDestroy()
       // 移除广播
       unregisterReceiver(scanResultReceiver)
   }
}

扫描WIFI

通过WifiManager扫描WIFI，并获取扫描结果，代码如下：

// 列表适配器
class WIFIAdapter : RecyclerView.Adapter<WIFIAdapter.WIFIViewHolder>() {
   private val wifiData = ArrayList<WIFIEntity>()
   override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): WIFIViewHolder {
       return WIFIViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.layout_wifi_item, parent, false))
   }
   override fun onBindViewHolder(holder: WIFIViewHolder, position: Int) {
       wifiData[position].run {
           holder.tvWifiName.text = wifiSSID
           holder.tvWifiSSID.text = wifiBSSID
           holder.ivWifiStrength.setImageResource(getStrengthIcon(wifiStrength))
           holder.ivNeedPassword.setImageResource(if (needPassword) R.drawable.icon_lock else R.drawable.icon_unlock)
       }
   }
   override fun getItemCount(): Int {
       return wifiData.size
   }
   fun setNewData(wifiData: ArrayList<WIFIEntity>?) {
       val lastItemCount = itemCount
       if (lastItemCount != 0) {
           this.wifiData.clear()
           notifyItemRangeRemoved(0, lastItemCount)
       }
       wifiData?.let { this.wifiData.addAll(it) }
       notifyItemChanged(0, itemCount)
   }
   private fun getStrengthIcon(wifiStrength: Int): Int {
       return when (wifiStrength) {
           0 -> R.drawable.wifi_strength_0
           1 -> R.drawable.wifi_strength_1
           2 -> R.drawable.wifi_strength_2
           else -> R.drawable.wifi_strength_3
       }
   }
   interface ItemClickListener {
       fun onItemClick(wifiInfo: WIFIEntity)
   }
   class WIFIViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
       val tvWifiName: AppCompatTextView = itemView.findViewById(R.id.tv_wifi_name)
       val tvWifiSSID: AppCompatTextView = itemView.findViewById(R.id.tv_wifi_ssid)
       val ivNeedPassword: AppCompatImageView = itemView.findViewById(R.id.iv_need_password)
       val ivWifiStrength: AppCompatImageView = itemView.findViewById(R.id.iv_wifi_strength)
   }
}
class WIFIExampleActivity : AppCompatActivity() {
   private lateinit var binding: LayoutWifiExampleActivityBinding
   private val wifiAdapter = WIFIAdapter()
   private var wifiManager: WifiManager? = null
   private var requestPermissionName: String = Manifest.permission.ACCESS_FINE_LOCATION
   private val requestSinglePermissionLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted: Boolean ->
       if (granted) {
           // 申请定位权限通过，扫描WIFI
           if (wifiManager?.isWifiEnabled == true) {
               wifiManager?.startScan()
           }
       } else {
           //未同意授权
           if (!shouldShowRequestPermissionRationale(requestPermissionName)) {
               //用户拒绝权限并且系统不再弹出请求权限的弹窗
               //这时需要我们自己处理，比如自定义弹窗告知用户为何必须要申请这个权限
           }
       }
   }
   private val scanResultReceiver = object : BroadcastReceiver() {
       override fun onReceive(context: Context?, intent: Intent?) {
           if (intent?.getBooleanExtra(WifiManager.EXTRA_RESULTS_UPDATED, false) == true) {
               val wifiData = ArrayList<WIFIEntity>()
               wifiManager?.scanResults?.forEach {
                   val ssid = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
                       it.wifiSsid.toString()
                   } else {
                       it.SSID
                   }
                   val bssid = it.BSSID
                   // 获取WIFI加密类型
                   val capabilities = it.capabilities
                   // 获取WIFI信号强度
                   val level = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
                       wifiManager?.calculateSignalLevel(it.level) ?: 0
                   } else {
                       WifiManager.calculateSignalLevel(it.level, 4)
                   }
                   wifiData.add(WIFIEntity(ssid, bssid, capabilities.contains("wpa", true) || capabilities.contains("web", true), capabilities, level))
               }
               // 根据信号强度降序排列
               wifiData.sortByDescending { it.wifiStrength }
               wifiAdapter.setNewData(wifiData)
           }
       }
   }
   override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)
       binding = DataBindingUtil.setContentView(this, R.layout.layout_wifi_example_activity)
       wifiManager = applicationContext.getSystemService(Context.WIFI_SERVICE) as WifiManager
       binding.includeTitle.tvTitle.text = "WIFI Example"
       binding.btnStartScan.setOnClickListener {
           // 检测定位权限
           if (ActivityCompat.checkSelfPermission(this, requestPermissionName) == PackageManager.PERMISSION_GRANTED) {
               if (wifiManager?.isWifiEnabled == true) {
                   wifiManager?.startScan()
               }
           } else {
               requestSinglePermissionLauncher.launch(requestPermissionName)
           }
       }
       binding.rvWifiInfo.adapter = wifiAdapter
       registerReceiver(scanResultReceiver, IntentFilter().apply {
           addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)
       })
   }
   override fun onDestroy() {
       super.onDestroy()
       unregisterReceiver(scanResultReceiver)
   }
}

效果如图：

示例

在示例Demo中添加了相关的演示代码。

ExampleDemo github

ExampleDemo gitee

来源：https://juejin.cn/post/7212074532340056123