Check Internet Connectivity In this example scaning for number of available wifi connections , Creating a broadcast receiver which will call...

Scan wifi Networks in Android

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• Check Internet Connectivity

In this example scaning for number of available wifi connections , Creating a broadcast receiver which will called when number of wifi connections changed.

Project Structure :

File : File : AndroidManifest.xml

Give wifi access permissions in mainifest.xml file

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" /> <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"     package="com.androidexample.wificonnections"     android:versionCode="1"     android:versionName="1.0" >       <uses-sdk         android:minSdkVersion="8"/>       <application         android:allowBackup="true"         android:icon="@drawable/ic_launcher"         android:label="@string/app_name"         android:theme="@style/AppTheme" >         <activity             android:name="com.androidexample.wificonnections.WifiConnections"             android:label="@string/app_name" >             <intent-filter>                 <action android:name="android.intent.action.MAIN" />                   <category android:name="android.intent.category.LAUNCHER" />             </intent-filter>         </activity>     </application>           <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />     <uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />       </manifest>

File : res/layout/activity_wifi_connections.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".WifiConnections" >       <TextView         android:id="@+id/mainText"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:layout_centerHorizontal="true"         android:layout_centerVertical="true"         android:text="@string/hello_world" />   </RelativeLayout>

File : src/WifiConnections.java

import java.util.List; import android.app.Activity; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.net.wifi.ScanResult; import android.net.wifi.WifiManager; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.widget.TextView; import android.widget.Toast;   public class WifiConnections extends Activity {           TextView mainText;     WifiManager mainWifi;     WifiReceiver receiverWifi;     List<ScanResult> wifiList;     StringBuilder sb = new StringBuilder();           public void onCreate(Bundle savedInstanceState) {                  super.onCreate(savedInstanceState);                 setContentView(R.layout.activity_wifi_connections);        mainText = (TextView) findViewById(R.id.mainText);                 // Initiate wifi service manager        mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);                 // Check for wifi is disabled        if (mainWifi.isWifiEnabled() == false)             {                   // If wifi disabled then enable it                 Toast.makeText(getApplicationContext(), "wifi is disabled..making it enabled",                 Toast.LENGTH_LONG).show();                                   mainWifi.setWifiEnabled(true);             }                 // wifi scaned value broadcast receiver        receiverWifi = new WifiReceiver();                 // Register broadcast receiver        // Broacast receiver will automatically call when number of wifi connections changed        registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));        mainWifi.startScan();        mainText.setText("Starting Scan...");     }       public boolean onCreateOptionsMenu(Menu menu) {         menu.add(0, 0, 0, "Refresh");         return super.onCreateOptionsMenu(menu);     }       public boolean onMenuItemSelected(int featureId, MenuItem item) {         mainWifi.startScan();         mainText.setText("Starting Scan");         return super.onMenuItemSelected(featureId, item);     }       protected void onPause() {         unregisterReceiver(receiverWifi);         super.onPause();     }       protected void onResume() {         registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));         super.onResume();     }           // Broadcast receiver class called its receive method     // when number of wifi connections changed           class WifiReceiver extends BroadcastReceiver {                   // This method call when number of wifi connections changed         public void onReceive(Context c, Intent intent) {                           sb = new StringBuilder();             wifiList = mainWifi.getScanResults();             sb.append("\n        Number Of Wifi connections :"+wifiList.size()+"\n\n");                           for(int i = 0; i < wifiList.size(); i++){                                   sb.append(new Integer(i+1).toString() + ". ");                 sb.append((wifiList.get(i)).toString());                 sb.append("\n\n");             }                           mainText.setText(sb);          }               } }