早期Android版本App内连接指定的WIFI还是比较简单的，但是随着Android版本的提升，限制也越来越多。以下是一套完整的Android 11以上的WIFI应用内主动连接方案。
第一步：添加到建议连接：
val wifiManager = getSystemService(WIFI_SERVICE) as WifiManager//一定要加，不然切换指定WIFI无效
wifiManager.removeNetworkSuggestions(wifiManager.networkSuggestions)
val suggestion = WifiNetworkSuggestion.Builder().setSsid(ssid).setWpa2Passphrase((pwd)).setIsAppInteractionRequired(false).build()
val suggestionsList = ArrayList<WifiNetworkSuggestion>()
suggestionsList.add(suggestion)
val status: Int = wifiManager.addNetworkSuggestions(suggestionsList)
if (status == WifiManager.STATUS_NETWORK_SUGGESTIONS_SUCCESS) {}但是这里有一个问题：这个是建议，不一定能连上。这就很让人难受！
第二步：监听网络状态：
private val networkCallback = object : ConnectivityManager.NetworkCallback() {override fun onAvailable(network: Network) {super.onAvailable(network)Log.d(TAG, "用户已连接到网络")val capabilities = mConnectivityManager!!.getNetworkCapabilities(network)Log.d(TAG, "$capabilities")if (capabilities?.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) == true) {// 获取当前连接的WiFi信息val wifiInfo = wifiManager!!.connectionInfoLog.d(TAG, "wifi info = $wifiInfo")if (wifiInfo.ssid == String.format("\"%s\"", TEST_WIFI_SSID))) {Log.d(TAG, "用户已连接到建议的网络")Prefs.isWifiConnected = truePrefs.currentWifiSsid = wifiInfo.ssid}}}override fun onUnavailable() {super.onUnavailable()Log.d(TAG, "用户未连接到建议的网络")clearWifiState()}}mConnectivityManager = getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager// 注册回调
val request = NetworkRequest.Builder().addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET).addTransportType(NetworkCapabilities.TRANSPORT_WIFI).build()
mConnectivityManager?.registerNetworkCallback(request, networkCallback)第三步：如果10s内未主动连接上，跳转到WIFI设置页（注意：到这个页面也会主动连接，目测基本100%成功率）
lifecycleScope.launch {delay(10_000)if (!Prefs.isWifiConnected) {val intent = Intent(Settings.ACTION_WIFI_SETTINGS)startActivity(intent)}}
