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!!.connectionInfo
                Log.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 = true
                    Prefs.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)
            }
        }