BroadcastReceiver Wifi无效

Question

我希望我的应用程序在wifi进入“离线”状态时发出通知。

我想出了通知部分。但我似乎无法弄清楚'无线检查'部分。 我读了一些关于BroadcastReceiver的内容，但我似乎无法得到它的工作。任何有用的链接？或示例代码？教程？

在此先感谢！

更新了代码。它的工作，但我需要它只给出一个通知时，WiFi下线。

public class MainActivity extends Activity { 

@Override 
protected void onCreate(Bundle savedInstanceState) {   

    super.onCreate(savedInstanceState); 
    this.registerReceiver(this.mConnReceiver, 
      new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION)); 
    setContentView(R.layout.activity_main); 
} 

private BroadcastReceiver mConnReceiver = new BroadcastReceiver() { 
    public void onReceive(Context context, Intent intent) { 
     boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false); 
     String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON); 
     boolean isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false); 

     NetworkInfo currentNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO); 
     NetworkInfo otherNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO); 

     if(currentNetworkInfo.isConnected()){ 

     }else{ 
      showNotification(); 
     } 
    } 
}; 

Answer 1

你可以尝试这样的事情

In Manifest.xml 
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> 
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 

In your application Code: 

public class BroadCastSampleActivity extends Activity { 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    this.registerReceiver(this.mConnReceiver, 
      new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION)); 
} 

private BroadcastReceiver mConnReceiver = new BroadcastReceiver() { 
    public void onReceive(Context context, Intent intent) { 
     boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false); 
     String reason = intent.getStringExtra(ConnectivityManager.EXTRA_REASON); 
     boolean isFailover = intent.getBooleanExtra(ConnectivityManager.EXTRA_IS_FAILOVER, false); 

     NetworkInfo currentNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_NETWORK_INFO); 
     NetworkInfo otherNetworkInfo = (NetworkInfo) intent.getParcelableExtra(ConnectivityManager.EXTRA_OTHER_NETWORK_INFO); 

     if(currentNetworkInfo.isConnected()){ 
      Toast.makeText(getApplicationContext(), "Connected", Toast.LENGTH_LONG).show(); 
     }else{ 
      Toast.makeText(getApplicationContext(), "Not Connected", Toast.LENGTH_LONG).show(); 
     } 
    } 
}; 
}