265

我正在开发一个用于检查互联网连接的 android 广播接收器。

问题是我的广播接收器被调用了两次。我希望它仅在网络可用时才被调用。如果它不可用,我不想通知。

这是广播接收器

public class NetworkChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {
        final ConnectivityManager connMgr = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        final android.net.NetworkInfo wifi = connMgr
                .getNetworkInfo(ConnectivityManager.TYPE_WIFI);

        final android.net.NetworkInfo mobile = connMgr
                .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

        if (wifi.isAvailable() || mobile.isAvailable()) {
            // Do something

            Log.d("Network Available ", "Flag No 1");
        }
    }
}

这是 manifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.broadcastreceiverforinternetconnection"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <receiver android:name=".NetworkChangeReceiver" >
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
                <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
            </intent-filter>
        </receiver>
    </application>

</manifest>
4

21 回答 21

254

回答您的第一个问题:您的广播接收器被调用了两次,因为

您添加了两个<intent-filter>

  1. 网络连接变化:
    <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />

  2. WiFi状态变化:
    <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />

只需使用一个:
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />.

它只会响应一个动作而不是两个动作。请参阅此处了解更多信息。

回答您的第二个问题(如果互联网连接可用,您希望接收者只呼叫一次):

你的代码很完美;您仅在互联网可用时通知。

更新

如果您只想检查手机是否与互联网连接,则可以使用此方法检查您的连接。

public boolean isOnline(Context context) {

    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = cm.getActiveNetworkInfo();
    //should check null because in airplane mode it will be null
    return (netInfo != null && netInfo.isConnected());
}
于 2013-03-29T09:39:35.907 回答
85
public class NetworkChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {
        if (checkInternet(context)) {
            Toast.makeText(context, "Network Available Do operations", Toast.LENGTH_LONG).show();
        }
    }

    boolean checkInternet(Context context) {
        ServiceManager serviceManager = new ServiceManager(context);
        return serviceManager.isNetworkAvailable()
    }
}

服务管理器.java

public class ServiceManager {

    Context context;

    public ServiceManager(Context base) {
        context = base;
    }

    public boolean isNetworkAvailable() {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = cm.getActiveNetworkInfo();
        return networkInfo != null && networkInfo.isConnected();
    }
}

权限:

 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 <uses-permission android:name="android.permission.INTERNET" />
于 2014-09-30T06:36:56.500 回答
62

每次使用广播接收器检查互联网状态:

互联网状态实现

Google Drive 上提供了完整的源代码

AndroidManifest.xml

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>
<receiver android:name=".receivers.NetworkChangeReceiver">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>
</receiver>

广播接收器

package com.keshav.networkchangereceiverexample.receivers;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;

import static com.keshav.networkchangereceiverexample.MainActivity.dialog;

public class NetworkChangeReceiver extends BroadcastReceiver
{
    @Override
    public void onReceive(Context context, Intent intent)
    {
        try
        {
            if (isOnline(context)) {
                dialog(true);
                Log.e("keshav", "Online Connect Intenet ");
            } else {
                dialog(false);
                Log.e("keshav", "Conectivity Failure !!! ");
            }
        } catch (NullPointerException e) {
            e.printStackTrace();
        }
    }

    private boolean isOnline(Context context) {
        try {
            ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo netInfo = cm.getActiveNetworkInfo();
            //should check null because in airplane mode it will be null
            return (netInfo != null && netInfo.isConnected());
        } catch (NullPointerException e) {
            e.printStackTrace();
            return false;
        }
    }
}

MainActivity.java

package com.keshav.networkchangereceiverexample;

import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.Color;
import android.net.ConnectivityManager;
import android.os.Build;
import android.os.Handler;
import android.os.Looper;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.TextView;

import com.keshav.networkchangereceiverexample.receivers.NetworkChangeReceiver;

public class MainActivity extends AppCompatActivity {

    private BroadcastReceiver mNetworkReceiver;
    static TextView tv_check_connection;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv_check_connection=(TextView) findViewById(R.id.tv_check_connection);
        mNetworkReceiver = new NetworkChangeReceiver();
        registerNetworkBroadcastForNougat();

    }

    public static void dialog(boolean value){

        if(value){
            tv_check_connection.setText("We are back !!!");
            tv_check_connection.setBackgroundColor(Color.GREEN);
            tv_check_connection.setTextColor(Color.WHITE);

            Handler handler = new Handler();
            Runnable delayrunnable = new Runnable() {
                @Override
                public void run() {
                    tv_check_connection.setVisibility(View.GONE);
                }
            };
            handler.postDelayed(delayrunnable, 3000);
        }else {
            tv_check_connection.setVisibility(View.VISIBLE);
            tv_check_connection.setText("Could not Connect to internet");
            tv_check_connection.setBackgroundColor(Color.RED);
            tv_check_connection.setTextColor(Color.WHITE);
        }
    }


    private void registerNetworkBroadcastForNougat() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
            registerReceiver(mNetworkReceiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
        }
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            registerReceiver(mNetworkReceiver, new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION));
        }
    }

    protected void unregisterNetworkChanges() {
        try {
            unregisterReceiver(mNetworkReceiver);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        unregisterNetworkChanges();
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.keshav.networkchangereceiverexample.MainActivity">

    <TextView
        android:id="@+id/tv_check_connection"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Connection establised !"
        android:padding="25dp"
        app:layout_constraintBottom_toBottomOf="parent"
        android:gravity="center"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</LinearLayout>
于 2017-07-03T09:02:00.320 回答
26

使用此方法检查网络状态:

private void checkInternetConnection() {

    if (br == null) {

        br = new BroadcastReceiver() {

            @Override
            public void onReceive(Context context, Intent intent) {

                Bundle extras = intent.getExtras();

                NetworkInfo info = (NetworkInfo) extras
                        .getParcelable("networkInfo");

                State state = info.getState();
                Log.d("TEST Internet", info.toString() + " "
                        + state.toString());

                if (state == State.CONNECTED) {
                      Toast.makeText(getApplicationContext(), "Internet connection is on", Toast.LENGTH_LONG).show();

                } else {
                       Toast.makeText(getApplicationContext(), "Internet connection is Off", Toast.LENGTH_LONG).show();
                }

            }
        };

        final IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver((BroadcastReceiver) br, intentFilter);
    }
}

记得在 onDestroy 中取消注册服务。

干杯!!

于 2015-09-04T05:32:55.047 回答
14

警告:Declaring a broadcastreceiver for android.net.conn.CONNECTIVITY_CHANGE is deprecated for apps targeting N and higher. In general, apps should not rely on this broadcast and instead use JobScheduler or GCMNetworkManager.

正如CONNECTIVITY_CHANGE已弃用的那样,我们应该使用另一种方式来做同样的事情

以下NetworkConnectionLiveData将处理到目前为止的所有操作系统版本,并且如果目标 SDK 小于Build.VERSION_CODES.LOLLIPOP那么只有我们可以使用broadcastReceiver

最好的部分是此类使用LiveData,因此无需注册任何接收器使用LiveData,它将处理所有事情

class NetworkConnectionLiveData(val context: Context) : LiveData<Boolean>() {

    private var connectivityManager: ConnectivityManager = context.getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager

    private lateinit var connectivityManagerCallback: ConnectivityManager.NetworkCallback

    override fun onActive() {
        super.onActive()
        updateConnection()
        when {
            Build.VERSION.SDK_INT >= Build.VERSION_CODES.N -> connectivityManager.registerDefaultNetworkCallback(getConnectivityManagerCallback())
            Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP -> lollipopNetworkAvailableRequest()
            else -> {
                if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
                    context.registerReceiver(networkReceiver, IntentFilter("android.net.conn.CONNECTIVITY_CHANGE"))
                }
            }
        }
    }

    override fun onInactive() {
        super.onInactive()
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            connectivityManager.unregisterNetworkCallback(connectivityManagerCallback)
        } else {
            context.unregisterReceiver(networkReceiver)
        }
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    private fun lollipopNetworkAvailableRequest() {
        val builder = NetworkRequest.Builder()
                .addTransportType(android.net.NetworkCapabilities.TRANSPORT_CELLULAR)
                .addTransportType(android.net.NetworkCapabilities.TRANSPORT_WIFI)
        connectivityManager.registerNetworkCallback(builder.build(), getConnectivityManagerCallback())
    }

    private fun getConnectivityManagerCallback(): ConnectivityManager.NetworkCallback {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {

            connectivityManagerCallback = object : ConnectivityManager.NetworkCallback() {
                override fun onAvailable(network: Network?) {
                    postValue(true)
                }

                override fun onLost(network: Network?) {
                    postValue(false)
                }
            }
            return connectivityManagerCallback
        } else {
            throw IllegalAccessError("Should not happened")
        }
    }

    private val networkReceiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context, intent: Intent) {
            updateConnection()
        }
    }

    private fun updateConnection() {
        val activeNetwork: NetworkInfo? = connectivityManager.activeNetworkInfo
        postValue(activeNetwork?.isConnected == true)
    }
} 

在任何类中使用 LiveData:

NetworkConnectionLiveData(context ?: return)
    .observe(viewLifecycleOwner, Observer { isConnected ->
        if (!isConnected) {
            // Internet Not Available
            return@Observer
        }
        // Internet Available
})
于 2020-04-07T14:29:23.027 回答
10

仅适用于想要动态注册广播的其他人:

BroadcastReceiver mWifiReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (checkWifiConnect()) {
            Log.d(TAG, "wifi has connected");
            // TODO
        }
    }
};

private void registerWifiReceiver() {
    IntentFilter filter = new IntentFilter();
    filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
    filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
    filter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
    mContext.registerReceiver(mWifiReceiver, filter);
}

private void unregisterWifiReceiver() {
    mContext.unregisterReceiver(mWifiReceiver);
}

private boolean checkWifiConnect() {
    ConnectivityManager manager = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = manager.getActiveNetworkInfo();
    if (networkInfo != null
            && networkInfo.getType() == ConnectivityManager.TYPE_WIFI
            && networkInfo.isConnected()) {
        return true;
    }
    return false;
}
于 2017-03-31T05:34:29.730 回答
9
public static boolean isNetworkAvailable(Context context) {
        boolean isMobile = false, isWifi = false;

        NetworkInfo[] infoAvailableNetworks = getConnectivityManagerInstance(
                context).getAllNetworkInfo();

        if (infoAvailableNetworks != null) {
            for (NetworkInfo network : infoAvailableNetworks) {

                if (network.getType() == ConnectivityManager.TYPE_WIFI) {
                    if (network.isConnected() && network.isAvailable())
                        isWifi = true;
                }
                if (network.getType() == ConnectivityManager.TYPE_MOBILE) {
                    if (network.isConnected() && network.isAvailable())
                        isMobile = true;
                }
            }
        }

        return isMobile || isWifi;
    }

/* You can write such method somewhere in utility class and call it NetworkChangeReceiver like below */
public class NetworkChangedReceiver extends BroadcastReceiver 
{
@Override
    public void onReceive(Context context, Intent intent) {

        if (isNetworkAvailable(context)) 
                {
             Toast.makeText(context, "Network Available Do operations",Toast.LENGTH_LONG).show(); 


    }
    }
}

仅当网络状态更改为已连接而不是断开连接时,才会调用上述广播接收器。

于 2013-11-27T07:29:17.463 回答
8

CONNECTIVITY_ACTION 文档

面向 Android 7.0(API 级别 24)及更高版本的应用如果在其清单中声明广播接收器,则不会收到此广播。如果应用程序使用 Context.registerReceiver() 注册其 BroadcastReceiver 并且该上下文仍然有效,它们仍将接收广播。

于 2017-07-05T03:32:38.573 回答
8

对于活动、片段或上下文,这是一种舒适的方式。如果您对活动/片段(在 onDestroy 中)执行此操作,它也会自动取消注册,如果您愿意:

abstract class ConnectionBroadcastReceiver : BroadcastReceiver() {
    companion object {
        @JvmStatic
        fun registerWithoutAutoUnregister(context: Context, connectionBroadcastReceiver: ConnectionBroadcastReceiver) {
            context.registerReceiver(connectionBroadcastReceiver, IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION))
        }

        @JvmStatic
        fun registerToFragmentAndAutoUnregister(context: Context, fragment: Fragment, connectionBroadcastReceiver: ConnectionBroadcastReceiver) {
            val applicationContext = context.applicationContext
            registerWithoutAutoUnregister(applicationContext, connectionBroadcastReceiver)
            fragment.lifecycle.addObserver(object : LifecycleObserver {
                @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
                fun onDestroy() {
                    applicationContext.unregisterReceiver(connectionBroadcastReceiver)
                }
            })
        }

        @JvmStatic
        fun registerToActivityAndAutoUnregister(activity: AppCompatActivity, connectionBroadcastReceiver: ConnectionBroadcastReceiver) {
            registerWithoutAutoUnregister(activity, connectionBroadcastReceiver)
            activity.lifecycle.addObserver(object : LifecycleObserver {
                @OnLifecycleEvent(Lifecycle.Event.ON_DESTROY)
                fun onDestroy() {
                    activity.unregisterReceiver(connectionBroadcastReceiver)
                }
            })
        }

        @JvmStatic
        fun hasInternetConnection(context: Context): Boolean {
            val info = (context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager).activeNetworkInfo
            return !(info == null || !info.isConnectedOrConnecting)
        }
    }

    override fun onReceive(context: Context, intent: Intent) {
        val hasConnection = !intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false)
//        Log.d("AppLog", "conenctivity changed. hasConnection? $hasConnection")
        onConnectionChanged(hasConnection)
    }

    abstract fun onConnectionChanged(hasConnection: Boolean)
}

片段中的用法:

    ConnectionBroadcastReceiver.registerToFragmentAndAutoUnregister(activity!!, this, object : ConnectionBroadcastReceiver() {
        override fun onConnectionChanged(hasConnection: Boolean) {
            // Log.d("AppLog", "onConnectionChanged:" + hasConnection)
        }
    })
于 2018-04-11T12:07:36.610 回答
7

试试这个

public class ConnectionBroadcastReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {


    if (<Check internet connection available >) { 
        Toast.makeText(context, "connect to the internet", Toast.LENGTH_LONG).show();

        /*upload background upload service*/
        Intent serviceIntent = new Intent(context,<your service class>);
        context.startService(serviceIntent);


    }else{
        Toast.makeText(context, "Connection failed", Toast.LENGTH_LONG).show();

    }
    }
}

一旦互联网连接触发,就会加载这个(BroadcastReciever)

于 2014-09-25T10:46:14.157 回答
7

我知道这个帖子很旧并且得到了充分的回答,但我觉得以下内容可能会对某些人有所帮助。

问题正文中的代码包含一个此处没有人解决的错误。@Nikhil 正在检查 wifi/手机是否可用,而不是是否已连接。

修复在这里:

@Override
public void onReceive(final Context context, final Intent intent) {
    final ConnectivityManager connMgr = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);

    final android.net.NetworkInfo wifi = connMgr
            .getNetworkInfo(ConnectivityManager.TYPE_WIFI);

    final android.net.NetworkInfo mobile = connMgr
            .getNetworkInfo(ConnectivityManager.TYPE_MOBILE);

    if (wifi.isConnected() || mobile.isConnected()) {
      // do stuff
    }
}
于 2016-06-06T09:34:25.897 回答
7

显现:

<receiver android:name=".your.namepackage.here.ConnectivityReceiver">
    <intent-filter>
        <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
    </intent-filter>
</receiver>

接收器类:

public class ConnectivityReceiver extends BroadcastReceiver{

    @Override
    public void onReceive(Context context, Intent intent) {
        final String action = intent.getAction();
        switch (action) {
            case ConnectivityManager.CONNECTIVITY_ACTION:
                DebugUtils.logDebug("BROADCAST", "network change");
                if(NetworkUtils.isConnect()){
                    //do action here
                }
            break;
        }
    }
}

和类实用程序,例如:

public class NetworkUtils {

    public static boolean isConnect() {
        ConnectivityManager connectivityManager = (ConnectivityManager) Application.getInstance().getSystemService(Context.CONNECTIVITY_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            Network[] netArray = connectivityManager.getAllNetworks();
            NetworkInfo netInfo;
            for (Network net : netArray) {
                netInfo = connectivityManager.getNetworkInfo(net);
                if ((netInfo.getTypeName().equalsIgnoreCase("WIFI") || netInfo.getTypeName().equalsIgnoreCase("MOBILE")) && netInfo.isConnected() && netInfo.isAvailable()) {
                    //if (netInfo.getState().equals(NetworkInfo.State.CONNECTED)) {
                    Log.d("Network", "NETWORKNAME: " + netInfo.getTypeName());
                    return true;
                }
            }
        } else {
            if (connectivityManager != null) {
                @SuppressWarnings("deprecation")
                NetworkInfo[] netInfoArray = connectivityManager.getAllNetworkInfo();
                if (netInfoArray != null) {
                    for (NetworkInfo netInfo : netInfoArray) {
                        if ((netInfo.getTypeName().equalsIgnoreCase("WIFI") || netInfo.getTypeName().equalsIgnoreCase("MOBILE")) && netInfo.isConnected() && netInfo.isAvailable()) {
                            //if (netInfo.getState() == NetworkInfo.State.CONNECTED) {
                            Log.d("Network", "NETWORKNAME: " + netInfo.getTypeName());
                            return true;
                        }
                    }
                }
            }
        }
        return false;
    }
}
于 2016-08-11T23:31:43.837 回答
3
public class AsyncCheckInternet extends AsyncTask<String, Void, Boolean> {

public static final int TIME_OUT = 10 * 1000;

private OnCallBack listener;

public interface OnCallBack {

    public void onBack(Boolean value);
}

public AsyncCheckInternet(OnCallBack listener) {
    this.listener = listener;
}

@Override
protected void onPreExecute() {
}

@Override
protected Boolean doInBackground(String... params) {

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

    NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();

    if ((networkInfo != null && networkInfo.isConnected())
            && ((networkInfo.getType() == ConnectivityManager.TYPE_WIFI) || (networkInfo
                    .getType() == ConnectivityManager.TYPE_MOBILE))) {
        HttpURLConnection urlc;
        try {
            urlc = (HttpURLConnection) (new URL("http://www.google.com")
                    .openConnection());
            urlc.setConnectTimeout(TIME_OUT);
            urlc.connect();
            if (urlc.getResponseCode() == HttpURLConnection.HTTP_OK) {
                return true;
            } else {
                return false;
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
            return false;

        } catch (IOException e) {
            e.printStackTrace();
            return false;

        }
    } else {
        return false;
    }
}

@Override
protected void onPostExecute(Boolean result) {
    if (listener != null) {
        listener.onBack(result);
    }
}

}

于 2015-12-24T09:51:42.013 回答
3

添加一个可以监听网络连接变化的广播接收器。然后检查设备是否连接到互联网或没有使用 ConnectivityManager。有关详细了解,请参阅此帖子视频。下面是代码:

public class NetworkStateChangeReceiver extends BroadcastReceiver {
  public static final String NETWORK_AVAILABLE_ACTION = "com.ajit.singh.NetworkAvailable";
  public static final String IS_NETWORK_AVAILABLE = "isNetworkAvailable";

  @Override
  public void onReceive(Context context, Intent intent) {
    Intent networkStateIntent = new Intent(NETWORK_AVAILABLE_ACTION);
    networkStateIntent.putExtra(IS_NETWORK_AVAILABLE,  isConnectedToInternet(context));
    LocalBroadcastManager.getInstance(context).sendBroadcast(networkStateIntent);
  }

  private boolean isConnectedToInternet(Context context) {
    try {
      if (context != null) {
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        return networkInfo != null && networkInfo.isConnected();
      }
      return false;
    } catch (Exception e) {
      Log.e(NetworkStateChangeReceiver.class.getName(), e.getMessage());
      return false;
    }
  }
}

我写这个接收器是为了在屏幕上显示一个通知,这就是为什么你会看到一个带有网络状态的本地广播。这是显示通知的代码。

public class MainActivity extends AppCompatActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    IntentFilter intentFilter = new IntentFilter(NetworkStateChangeReceiver.NETWORK_AVAILABLE_ACTION);
    LocalBroadcastManager.getInstance(this).registerReceiver(new BroadcastReceiver() {
      @Override
      public void onReceive(Context context, Intent intent) {
        boolean isNetworkAvailable = intent.getBooleanExtra(IS_NETWORK_AVAILABLE, false);
        String networkStatus = isNetworkAvailable ? "connected" : "disconnected";

        Snackbar.make(findViewById(R.id.activity_main), "Network Status: " + networkStatus, Snackbar.LENGTH_LONG).show();
      }
    }, intentFilter);
  }
}

Activity 监听网络接收器广播的意图,并在屏幕上显示通知。

于 2016-10-28T14:49:54.893 回答
2

完整答案在这里

清单文件

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

<receiver android:name=".NetworkStateReceiver">
    <intent-filter>
      <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
    </intent-filter>
  </receiver>

BroadecardReceiver 类

public class NetworkStateReceiver extends BroadcastReceiver {
    public void onReceive(Context context, Intent intent) {
     Log.d("app","Network connectivity change");
     if(intent.getExtras()!=null) {
        NetworkInfo ni=(NetworkInfo) intent.getExtras().get(ConnectivityManager.EXTRA_NETWORK_INFO);
        if(ni!=null && ni.getState()==NetworkInfo.State.CONNECTED) {
            Log.i("app","Network "+ni.getTypeName()+" connected");
        } else if(intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY,Boolean.FALSE)) {
            Log.d("app","There's no network connectivity");
        }
   }
}

注册接收器MainActivity

@Override
protected void onResume() {
    super.onResume();
    IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
    registerReceiver(networkReceiver, intentFilter);
}

@Override
protected void onPause() {
    super.onPause();
    if (networkReceiver != null)
        unregisterReceiver(networkReceiver);
}

享受!

于 2019-12-10T11:31:34.530 回答
1

广播接收器代码以检查互联网连接变化:

public class BroadCastDetecter extends BroadcastReceiver {
    public static boolean internet_status = false;
    public static void checkInternetConenction(Context context) {
        internet_status = false;
        ConnectivityManager check = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (check != null) {
            NetworkInfo[] info = check.getAllNetworkInfo();
            if (info != null)
                for (int i = 0; i < info.length; i++)
                {
                    if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                        internet_status = true;
                    }
                }
            if(internet_status)
            {
               //do what you want to if internet connection is available
            }
        }
    }

    @Override
    public void onReceive(Context context, Intent intent)
    {
        try {
            checkInternetConenction(context);
        }catch(Exception e){

        }
    }
}

在清单文件中添加:

 <receiver android:name=".BroadCastDetecter">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>
        </receiver>
于 2017-09-15T06:49:32.570 回答
1

这仅检查网络接口是否可用,并不能保证特定的网络服务可用,例如,可能存在低信号或服务器停机时间

  private boolean isNetworkInterfaceAvailable(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }

如果您想建立真正的连接以确保您的连接可以从服务器或任何 url 收集数据:

  private boolean isAbleToConnect(String url, int timeout) {
        try {
            URL myUrl = new URL(url);
            URLConnection connection = myUrl.openConnection();
            connection.setConnectTimeout(timeout);
            connection.connect();
            return true;
        } catch (Exception e) {
            Log.i("exception", "" + e.getMessage());
            return false;
        }
    }

此函数需要包装在后台线程中:

final String action = intent.getAction();
        if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
            checkConnectivity(context);
        }
    }


    private void checkConnectivity(final Context context) {
        if (!isNetworkInterfaceAvailable(context)) {
            Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
            return;
        }

        final Handler handler = new Handler();
        new Thread(new Runnable() {
            @Override
            public void run() {
                final boolean isConnected = isAbleToConnect("http://www.google.com", 1000);
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        if (isConnected)
                            Toast.makeText(context, "You are ONLINE!", Toast.LENGTH_SHORT).show();
                        else
                            Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
                    }
                });

            }
        }).start();

    }

添加所需权限:

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

在清单文件中的应用程序下添加此行:

android:usesCleartextTraffic="true"

将接收器添加到清单文件:

<receiver android:name=".ConnectivityChangeReceiver" >
            <intent-filter>

                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>
        </receiver>    

在您的活动中注册/取消注册 BR:

@Override
    protected void onStart() {
        super.onStart();
        IntentFilter filter = new IntentFilter("android.net.conn.CONNECTIVITY_CHANGE");
        registerReceiver(connectivityChangeReceiver, filter);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(connectivityChangeReceiver);
    }

这是整个广播类:

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Handler;
import android.util.Log;
import android.widget.Toast;

import java.net.URL;
import java.net.URLConnection;

public class ConnectivityChangeReceiver extends BroadcastReceiver {


    @Override
    public void onReceive(final Context context, final Intent intent) {

        final String action = intent.getAction();
        if (intent.getAction().equals(ConnectivityManager.CONNECTIVITY_ACTION)) {
            checkConnectivity(context);
        }
    }


    private void checkConnectivity(final Context context) {
        if (!isNetworkInterfaceAvailable(context)) {
            Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
            return;
        }

        final Handler handler = new Handler();
        new Thread(new Runnable() {
            @Override
            public void run() {
                final boolean isConnected = isAbleToConnect("http://www.google.com", 1000);
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        if (isConnected)
                            Toast.makeText(context, "You are ONLINE!", Toast.LENGTH_SHORT).show();
                        else
                            Toast.makeText(context, "You are OFFLINE!", Toast.LENGTH_SHORT).show();
                    }
                });

            }
        }).start();

    }

    //This only checks if the network interface is available, doesn't guarantee a particular network service is available, for example, there could be low signal or server downtime
    private boolean isNetworkInterfaceAvailable(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        return activeNetwork != null && activeNetwork.isConnectedOrConnecting();
    }

    //This makes a real connection to an url and checks if you can connect to this url, this needs to be wrapped in a background thread
    private boolean isAbleToConnect(String url, int timeout) {
        try {
            URL myUrl = new URL(url);
            URLConnection connection = myUrl.openConnection();
            connection.setConnectTimeout(timeout);
            connection.connect();
            return true;
        } catch (Exception e) {
            Log.i("exception", "" + e.getMessage());
            return false;
        }
    }
} 
于 2019-05-18T21:30:05.663 回答
1

1)在清单中: - 像下面的代码一样调用接收器

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.safal.checkinternet">

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        tools:ignore="AllowBackup,GoogleAppIndexingWarning">
        <receiver android:name=".NetworkChangeReceiver" >
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>
        </receiver>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

2)制作一个广播接收器类: - 在这个类中添加网络检查代码

package com.safal.checkinternet;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;
import android.widget.Toast;

public class NetworkChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {
        if (isOnline(context)){
            Toast.makeText(context, "Available", Toast.LENGTH_SHORT).show();
        }else {
            Toast.makeText(context, "Not Available", Toast.LENGTH_SHORT).show();
        }
    }
    public boolean isOnline(Context context) {

        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        assert cm != null;
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        return (netInfo != null && netInfo.isConnected());
    }    
} 

3)在您对广播接收器的活动调用中:-

package com.safal.checkinternet;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
//Call Broad cast Receiver 
        IntentFilter filter = new IntentFilter();
        filter.addAction("android.net.conn.CONNECTIVITY_CHANGE");
        registerReceiver(new NetworkChangeReceiver(), filter);
    }
}
于 2020-02-21T11:37:45.433 回答
0

更容易使用https://github.com/JobGetabu/DroidNet

 @Override
    public void onInternetConnectivityChanged(boolean isConnected) {

        if (isConnected) {
            //do Stuff with internet
            netIsOn();
        } else {
            //no internet
            netIsOff();
        }
    }

    private void netIsOn(){...}

    private void netIsOff(){...}
于 2019-02-22T21:10:36.390 回答
0

添加权限:

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

创建接收器以检查连接

public class NetworkChangeReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(final Context context, final Intent intent) {

        if(checkInternet(context))
        {
            Toast.makeText(context, "Network Available Do operations",Toast.LENGTH_LONG).show(); 
        }

    }

    boolean checkInternet(Context context) {
        ServiceManager serviceManager = new ServiceManager(context);
        if (serviceManager.isNetworkAvailable()) {
            return true;
        } else {
            return false;
        }
    }

}

服务管理器.java

public class ServiceManager {

    Context context;

    public ServiceManager(Context base) {
        context = base;
    }

    public boolean isNetworkAvailable() {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = cm.getActiveNetworkInfo();
        return networkInfo != null && networkInfo.isConnected();
    }
}
于 2020-02-11T10:06:35.627 回答
-1

首先,我们将创建一个类来检查网络状态的连通性。所以让我们创建一个类:

public class AppStatus {
    private static AppStatus instance = new AppStatus();
    static Context context;
    ConnectivityManager connectivityManager;
    NetworkInfo wifiInfo, mobileInfo;
    boolean connected = false;

    public static AppStatus getInstance(Context ctx) {
        context = ctx.getApplicationContext();
        return instance;
    }

    public boolean isOnline() {
        try {
            connectivityManager = (ConnectivityManager) context
                    .getSystemService(Context.CONNECTIVITY_SERVICE);

            NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
            connected = networkInfo != null && networkInfo.isAvailable() &&
                    networkInfo.isConnected();
            return connected;


        } catch (Exception e) {
            System.out.println("CheckConnectivity Exception: " + e.getMessage());
            Log.v("connectivity", e.toString());
        }
        return connected;
    }
}

现在制作一个新的广播接收器类:

public class ConnectivityReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (AppStatus.getInstance(context).isOnline()) {

            Intent intent1=new Intent(context,DisplayAct.class);
            intent1.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(intent1);




        } else {

            Toast.makeText(context, "Please !! Make your network ON", Toast.LENGTH_SHORT).show();

        }
    }
}

现在在清单上注册您的广播接收器:

<receiver android:name=".ConnectivityReceiver">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
            </intent-filter>
        </receiver>
于 2018-08-11T09:39:03.913 回答