Scanning Wifi networks and Finding Strongest network in Android

main.xml:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical" >

    <Button

        android:id="@+id/Scan"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="Scan" >

    </Button>

    <ScrollView

        android:id="@+id/Scroll"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" >

        <TextView

            android:id="@+id/Status"

            android:layout_width="fill_parent"

            android:layout_height="wrap_content"

            android:text="WiFiDemo" />

    </ScrollView>

</LinearLayout>

WiFiScanReceiver.java:

package com.wifiapp1.inspire.ram;

import java.util.List;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.net.wifi.ScanResult;

import android.net.wifi.WifiManager;

import android.widget.Toast;

public class WiFiScanReceiver extends BroadcastReceiver {

  WifiApp1Activity wifiDemo;

  public WiFiScanReceiver(WifiApp1Activity wifiDemo) {

    super();

    this.wifiDemo = wifiDemo;

  }

  @Override

  public void onReceive(Context c, Intent intent) {

    List<ScanResult> results = wifiDemo.wifi.getScanResults();

    ScanResult bestSignal = null;

    for (ScanResult result : results) {

      if (bestSignal == null

          || WifiManager.compareSignalLevel(bestSignal.level, result.level) < 0)

        bestSignal = result;

    }

    String message = String.format("%s networks found. %s is the strongest.",

        results.size(), bestSignal.SSID);

    Toast.makeText(wifiDemo, message, Toast.LENGTH_LONG).show();

   

  }

}

WifiApp1Activity.java:

package com.wifiapp1.inspire.ram;

import java.util.List;

import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.IntentFilter;

import android.net.wifi.WifiConfiguration;

import android.net.wifi.WifiInfo;

import android.net.wifi.WifiManager;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.TextView;

import android.widget.Toast;

public class WifiApp1Activity extends Activity implements OnClickListener {

WifiManager wifi;

BroadcastReceiver receiver;

TextView textStatus;

Button buttonScan;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

// Setup UI

textStatus = (TextView) findViewById(R.id.Status);

buttonScan = (Button) findViewById(R.id.Scan);

buttonScan.setOnClickListener(this);

// Setup WiFi

wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);

// Get WiFi status

WifiInfo info = wifi.getConnectionInfo();

textStatus.append("\n\nWiFi Status: " + info.toString());

// List available networks

List<WifiConfiguration> configs = wifi.getConfiguredNetworks();

for (WifiConfiguration config : configs) {

textStatus.append("\n\n" + config.toString());

}

// Register Broadcast Receiver

if (receiver == null)

receiver = new WiFiScanReceiver(this);

registerReceiver(receiver, new IntentFilter(

WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));

}

public void onClick(View view) {

Toast.makeText(this, "Scanning.......",

Toast.LENGTH_LONG).show();

 

wifi.startScan();

}

}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

    package="com.wifiapp1.inspire.ram"

    android:versionCode="1"

    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />

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

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

    <application

        android:icon="@drawable/ic_launcher"

        android:label="@string/app_name" >

        <activity

            android:name=".WifiApp1Activity"

            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>

</manifest>