如何在 API 级别 21 以下的设备中检查 NO INTERNET

Posted 2023-04-15

【中文标题】如何在 API 级别 21 以下的设备中检查 NO INTERNET

【英文标题】：how to check for NO INTERNET in devices below API level 21

【发布时间】：2020-10-18 15:57:54

【问题描述】：

这是我的 MainActivity，我已经在 onstart 中注册了我的网络调用。在此代码中，无论设备是否打开互联网 wifi，都不会调用 onUnavailable()。我想在点击一个按钮后检查互联网，如果互联网连接，它将继续下一个活动，否则没有

public class MainActivity extends AppCompatActivity 
    private TextView textView;
    ConnectivityManager.NetworkCallback networkCallback;
    ConnectivityManager manager;
    public static final String TAG = "bantai";
    private NetworkRequest networkRequest;


    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = findViewById(R.id.internetTextview);
        networkRequest = new NetworkRequest.Builder().build();
        manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);


        networkCallback = new ConnectivityManager.NetworkCallback() 
            @Override
            public void onAvailable(@NonNull Network network) 
                super.onAvailable(network);
                Log.d(TAG, "onAvailable: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("onAvailable");
                    
                );

            

            @Override
            public void onLosing(@NonNull Network network, int maxMsToLive) 
                super.onLosing(network, maxMsToLive);
                Log.d(TAG, "onLosing: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("loosing");
                    
                );
            

            @Override
            public void onLost(@NonNull Network network) 
                super.onLost(network);
                Log.d(TAG, "onLost: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("lost");
                    
                );            

            @Override
            public void onUnavailable() 
                super.onUnavailable();
                Log.d(TAG, "onUnavailable: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("unavailable");
                    
                );            

            @Override
            public void onCapabilitiesChanged(@NonNull Network network, @NonNull NetworkCapabilities networkCapabilities) 
                super.onCapabilitiesChanged(network, networkCapabilities);
                Log.d(TAG, "onCapabilitiesChanged: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("capability");
                    
                );            

            @Override
            public void onLinkPropertiesChanged(@NonNull Network network, @NonNull LinkProperties linkProperties) 
                super.onLinkPropertiesChanged(network, linkProperties);
                Log.d(TAG, "onLinkPropertiesChanged: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("link");
                    
                );            

            @Override
            public void onBlockedStatusChanged(@NonNull Network network, boolean blocked) 
                super.onBlockedStatusChanged(network, blocked);
                Log.d(TAG, "onBlockedStatusChanged: ");
                runOnUiThread(new Runnable() 
                    @Override
                    public void run() 
                        Log.d(TAG, "onAvailable: "+ Thread.currentThread().getName());
                        textView.setText("blocked");
                    
                );            
        ;
    

    @Override
    protected void onStart() 
        super.onStart();
        manager.requestNetwork(networkRequest,networkCallback);

    

    @Override
    protected void onStop() 
        super.onStop();
        manager.unregisterNetworkCallback(networkCallback);
    

还有ConnectivityManager.requestNetwork(networkRequest, networkCallback, 3000)这个命令需要Api level 21 +，超时3秒。

【问题讨论】：

github.com/jumaallan/androidNetworkManager - 参考这个开源。

这能回答你的问题吗？ Android check internet connection

是的，当时工作正常，但现在 networkinfo、activenetworkinfo 和 getactivenetwork 已弃用

【参考方案1】：

为了方便查看互联网，请使用此功能，它在 api 16 及更高版本上响应：

在 AndroidManifest.xml 中添加：

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

现在检查网络状态：

getActiveNetworkInfo 在 API 29 上已弃用。

getAllNetworkInfo 在 API 23 上已弃用。

fun isConnected(): Boolean 

 val hasInternet: Boolean

 val connectivityManager =
     ctx.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager

 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) 
     val networkCapabilities = connectivityManager.activeNetwork ?: return false
     val actNw =
         connectivityManager.getNetworkCapabilities(networkCapabilities) ?: return false
     hasInternet = when 
         actNw.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> true
         actNw.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> true
         actNw.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> true
         else -> false
     
  else 
     hasInternet = try 
         if (connectivityManager.activeNetworkInfo == null) 
             false
          else 
             connectivityManager.activeNetworkInfo?.isConnected!!
         
      catch (e: Exception) 
         false
     
 
 return hasInternet

【讨论】：

对不起，妈妈，我不知道 Kotlin，这就是为什么如果有人说它有效，我无法将其标记为正确，我会标记它