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>
回答第一个问题:您的广播接收器被调用了两次，因为
您已经添加了两个<intent-filter>
网络连接的改变:
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
WiFi状态变化:
<action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
就用一个:
<action android:name="android.net.conn.CONNECTIVITY_CHANGE" />。
它将只响应一个操作而不是两个。更多信息请参见这里。
回答你的第二个问题(如果可以上网，你想让对方只打一次电话):
你的代码是完美的;只有在互联网可用时才通知。
更新
如果你只是想检查手机是否与互联网相连，你可以使用这种方法来检查你的连接。
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());
}
到2022年，上述BroadcastReceiver方法都将失效。由于Android 7.0的限制，BroadcastReceiver方法将不再工作。检查互联网是否可用的最新和最简单的方法是使用以下代码。(Android 12测试)
val networkRequest = NetworkRequest.Builder()
.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
.addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
.addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
.build()
private val networkCallback = object : ConnectivityManager.NetworkCallback() {
// network is available for use
override fun onAvailable(network: Network) {
super.onAvailable(network)
}
// Network capabilities have changed for the network
override fun onCapabilitiesChanged(
network: Network,
networkCapabilities: NetworkCapabilities
) {
super.onCapabilitiesChanged(network, networkCapabilities)
val unmetered = networkCapabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
}
// lost network connection
override fun onLost(network: Network) {
super.onLost(network)
}
}
val connectivityManager = getSystemService(ConnectivityManager::class.java) as ConnectivityManager
connectivityManager.requestNetwork(networkRequest, networkCallback
将这段代码放在一个函数中，并在activity/fragment的onCreate()中调用它。在onAvailable()和onLost()函数中，每当互联网连接或断开连接时，您都会收到通知。与此同时，您可以使用liveData或任何您喜欢的方式在其他活动/片段中广播这些更新。
官方文档链接:https://developer.android.com/training/monitoring-device-state/connectivity-status-type
1)在manifest: -调用接收器如下代码
<?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)创建一个宽播接收器类:在这个类中添加网络检查的代码
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)在您的活动中呼叫广播接收器:-
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);
}
}
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;
}
}
