Scan wifi connections or Get number of available wifi connections

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);  
        }
        
    }
}