Android 获取 Wifi 连接状态

问题描述

我目前正在使用 NetworkRequest 和 NetworkCallback 方法（由 Google 官方推荐）来获取 Wifi 连接状态，并且部分工作。

我希望 onUnavailable() 会在以下情况下被调用：close app -> turn off Wifi -> launch app，但是什么也没发生：

private fun getNetworkRequest(): NetworkRequest {
    return NetworkRequest.Builder()
        .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)    //restric to Wifi type only
        .build()
}

private fun getNetworkCallBack(): ConnectivityManager.NetworkCallback {
    return object : ConnectivityManager.NetworkCallback() {
        override fun onAvailable(network: Network) {            //works
            super.onAvailable(network)

            Toast.makeText(requireContext(),"Wifi is on!",Toast.LENGTH_SHORT).show()
        }

        override fun onLost(network: Network) {                 //works
            super.onLost(network)

            Toast.makeText(requireContext(),"Wifi turns off!",Toast.LENGTH_SHORT).show()
        }

        override fun onUnavailable() {                          //not works as expected
            super.onUnavailable()

            Toast.makeText(requireContext(),"Wifi unavailable!",Toast.LENGTH_SHORT).show()
        }
    }
}

fun Fragment.getConnectivityManager() = requireContext().getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

override fun onResume() {
    super.onResume()

    getConnectivityManager().registerNetworkCallback(networkRequest,networkCallback)
}

解决方法

好的，我找到了解决方案：

val isWifiOn = with(getConnectivityManager()) {
    getNetworkCapabilities(activeNetwork)?.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
}

演示：https://youtu.be/OHFrtXVW4x4