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。我希望它只在网络可用时被调用。如果它不可用,我不想被通知。

这是广播接收机

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>

当前回答

对于想动态注册广播的人:

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;
}

其他回答

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中注销服务。

干杯! !

清单:

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

接收方的类:

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utils,如example:

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;
    }
}

这只检查网络接口是否可用,并不保证特定的网络服务可用,例如,可能有低信号或服务器停机

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

如果你想建立一个真正的连接,以确保你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;
        }
    }

这个函数需要被包装在后台线程中:

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manifest文件的application下添加以下一行:

android:usesCleartextTraffic="true"

将接收者添加到清单文件:

<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Broadcast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;
        }
    }
} 

CONNECTIVITY_ACTION文档:

针对Android 7.0 (API级别24)及以上的应用程序,如果它们在manifest中声明了广播接收器,则不会接收此广播。如果应用程序向context . registerreceiver()注册了BroadcastReceiver,并且该context仍然有效,那么应用程序仍然会接收广播。

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);
    }
}

}