ConnectivityManager只能检测连接，而不能检测网络可用性

Question

下面的代码用于检测网络连接。这种情况是软件连接到手机的热点，但手机的蜂窝网络没有开机。下面的代码返回isConnected = true，这意味着它只检测连通性？问题是我如何更改它以检测网络可用性？

fun Context.isOnline(): Boolean {
val connectivityManager =
    this.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
val networkInfo = connectivityManager.activeNetworkInfo

if (networkInfo == null) {
    log(message = "Network info is **NULL**")
    return false
} else {
    val isConnected = when(networkInfo.detailedState) {
        NetworkInfo.DetailedState.CONNECTING -> true
        NetworkInfo.DetailedState.AUTHENTICATING -> true
        NetworkInfo.DetailedState.OBTAINING_IPADDR -> true
        NetworkInfo.DetailedState.CONNECTED -> true
        NetworkInfo.DetailedState.VERIFYING_POOR_LINK -> true
        else -> false
    }

    if (!isConnected) {
        log(message = "Network state is **${networkInfo.detailedState?.name ?: "NULL"}**")
    }

    return isConnected
}

}

Answer 1

您正在对NetworkInfo使用已弃用的API。您应该使用NetworkCapabilities.NET_CAPABILITY_VALIDATED

表示已成功验证此网络上的连通性。例如，对于具有NET_CAPABILITY_INTERNET的网络，这意味着已成功检测到互联网连接。

SDK >= 23

您可以将您的代码更改为类似下面的代码，以查看这是否是用于确认互联网连接的true：

connectivityManager
.getNetworkCapabilities(connectivityManager.getActiveNetwork())
.hasCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)

软件开发工具包>= 21

如果您使用的是SDK21之前的版本，可以使用ConnectivityManager.registerNetworkCallback接口。

boolean isConnected = false;

final NetworkRequest request =
  new NetworkRequest.Builder()
  .addCapability(NetworkCapabilities.NET_CAPABILITY_VALIDATED)
  .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
  .build();

final ConnectivityManager connectivityManager = (ConnectivityManager)
  context.getSystemService(Context.CONNECTIVITY_SERVICE);

final NetworkCallback networkCallback = new NetworkCallback() {
  @Override
  void onAvailable(Network network) {
      // Triggers when this network is available.
      isConnected = true;
  }

  @Override
  void onLost(Network network) {
      // Triggers when this network is lost.
      isConnected = false;
  }
};

connectivityManager.requestNetwork(request, networkCallback);