Wi-Fi device scanning in Android

Hello Friend!

I am going to share code for Wi-Fi device scanning and getting their states. Important step are given below-

1-Create an android project.

2-Create a class WiFiDemo.

3-Create another class WiFiScaner for searching Wi-Fi devices.

4- Change in main.xml file.

5-Add Wi-Fi permission in manifest file.

a)Print Screen:

b)manifest.xml

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

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

package="com.manish.wifi.demo"

android:versionCode="1"

android:versionName="1.0" >

<uses-sdk android:minSdkVersion="8" />

<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:label="@string/app_name"

android:name=".WiFiDemo" >

<intent-filter >

<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

</activity>

</application>

</manifest>

c)WiFiDemo.java

package com.manish.wifi.demo;

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.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.TextView;

import android.widget.Toast;

public class WiFiDemo extends Activity implements OnClickListener {

private static final String TAG = "WiFiDemo";

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.textStatus);

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

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 WiFiScaner(this);

registerReceiver(receiver, new IntentFilter(

WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));

Log.d(TAG, "onCreate()");

}

@Override

public void onStop() {

unregisterReceiver(receiver);

}

public void onClick(View view) {

Toast.makeText(this, "All network serched!!!", Toast.LENGTH_LONG)

.show();

if (view.getId() == R.id.buttonScan) {

Log.d(TAG, "onClick() wifi.startScan()");

wifi.startScan();

}

}

}

d)WiFiScaner.java

package com.manish.wifi.demo;

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.util.Log;

import android.widget.Toast;

public class WiFiScaner extends BroadcastReceiver {

private static final String TAG = "WiFiScanReceiver";

WiFiDemo wifiDemo;

public WiFiScaner(WiFiDemo 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();

Log.d(TAG, "onReceive() message: " + message);

}

}

e)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/buttonScan"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="Search Network" >

</Button>

<ScrollView

android:id="@+id/ScrollView01"

android:layout_width="wrap_content"

android:layout_height="wrap_content" >

<TextView

android:id="@+id/textStatus"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="WiFiDemo"

android:gravity="center"/>

</ScrollView>

</LinearLayout>