Android掃描wifi熱點代碼

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;

public class WifiTester 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.main); 
    mainText = (TextView) findViewById(R.id.mainText); 
    mainWifi = (WifiManager) getSystemService(Context.WIFI_SERVICE); 

    receiverWifi = new WifiReceiver(); 
    registerReceiver(receiverWifi, new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)); 
    mainWifi.startScan(); 
    mainText.setText("\nStarting Scan...\n"); 
} 

 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(); 
 } 

 class WifiReceiver extends BroadcastReceiver { 
      public void onReceive(Context c, Intent intent) { 
           sb = new StringBuilder(); 
           wifiList = mainWifi.getScanResults(); 
         for(int i = 0; i < wifiList.size(); i++){ 
           sb.append(new Integer(i+1).toString() + "."); 
           sb.append((wifiList.get(i)).toString()); 
           sb.append("\n"); 
         } 
         mainText.setText(sb); 
      } 
 } 


}</pre> 

 同時需要申請如下權限
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission> 
<uses-permission android:name="android.permission.ACCESS_CHECKIN_PROPERTIES"></uses-permission> 
<uses-permission android:name="android.permission.WAKE_LOCK"></uses-permission> 
<uses-permission android:name="android.permission.INTERNET"></uses-permission> 
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission> 
<uses-permission android:name="android.permission.MODIFY_PHONE_STATE"></uses-permission>