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>
添加权限:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
创建Receiver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;
}
}
}
ServiceManager.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();
}
}
每次使用广播接收器检查互联网状态:
谷歌驱动器上可用的完整源代码。
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>
BroadcastReciever
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>
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，这(BroadcastReciever)将被加载
这里有一种适合活动、片段或上下文的方法。它也会自动注销，如果你做的活动/片段(在onDestroy)，如果你希望:
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)
}
在片段中的用法:
ConnectionBroadcastReceiver.registerToFragmentAndAutoUnregister(activity!!, this, object : ConnectionBroadcastReceiver() {
override fun onConnectionChanged(hasConnection: Boolean) {
// Log.d("AppLog", "onConnectionChanged:" + hasConnection)
}
})
我知道这个帖子已经很老了，而且已经有了完整的答案，但我觉得下面的帖子可能会帮助到一些人。
问题主体中的代码包含一个这里没有人解决的错误。
@Nikhil正在检查wifi/手机是否可用，而不是是否连接。
解决方法如下:
@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
}
}
