<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="fill_parent"><LinearLayoutandroid:orientation="vertical"  android:layout_width="fill_parent"  android:layout_height="fill_parent"  >
<Button  android:id="@+id/scan"  android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:text="扫描网络"  />
<Button  android:id="@+id/start"  android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:text="打开Wifi"  />
<Button  android:id="@+id/stop"  android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:text="关闭Wifi"  />
<Button  android:id="@+id/check"  android:layout_width="wrap_content"   android:layout_height="wrap_content"   android:text="Wifi状态"  />  <TextView  android:id="@+id/allNetWork"  android:layout_width="fill_parent"  android:layout_height="wrap_content"   android:text="当前没有扫描到Wifi网络"  />  </LinearLayout>
</ScrollView>

import java.util.List;import android.content.Context;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiInfo;
import android.net.wifi.WifiManager;
import android.net.wifi.WifiManager.WifiLock;public class WifiAdmin {//定义一个WifiManager对象private WifiManager mWifiManager;//定义一个WifiInfo对象private WifiInfo mWifiInfo;//扫描出的网络连接列表private List<ScanResult> mWifiList;//网络连接列表private List<WifiConfiguration> mWifiConfigurations;WifiLock mWifiLock;public WifiAdmin(Context context){//取得WifiManager对象mWifiManager=(WifiManager) context.getSystemService(Context.WIFI_SERVICE);//取得WifiInfo对象mWifiInfo=mWifiManager.getConnectionInfo();}//打开wifipublic void openWifi(){if(!mWifiManager.isWifiEnabled()){mWifiManager.setWifiEnabled(true);}}//关闭wifipublic void closeWifi(){if(!mWifiManager.isWifiEnabled()){mWifiManager.setWifiEnabled(false);}}// 检查当前wifi状态  public int checkState() {  return mWifiManager.getWifiState();  }  //锁定wifiLockpublic void acquireWifiLock(){mWifiLock.acquire();}//解锁wifiLockpublic void releaseWifiLock(){//判断是否锁定if(mWifiLock.isHeld()){mWifiLock.acquire();}}//创建一个wifiLockpublic void createWifiLock(){mWifiLock=mWifiManager.createWifiLock("test");}//得到配置好的网络public List<WifiConfiguration> getConfiguration(){return mWifiConfigurations;}//指定配置好的网络进行连接public void connetionConfiguration(int index){if(index>mWifiConfigurations.size()){return ;}//连接配置好指定ID的网络mWifiManager.enableNetwork(mWifiConfigurations.get(index).networkId, true);}public void startScan(){mWifiManager.startScan();//得到扫描结果mWifiList=mWifiManager.getScanResults();//得到配置好的网络连接mWifiConfigurations=mWifiManager.getConfiguredNetworks();}//得到网络列表public List<ScanResult> getWifiList(){return mWifiList;}//查看扫描结果public StringBuffer lookUpScan(){StringBuffer sb=new StringBuffer();for(int i=0;i<mWifiList.size();i++){sb.append("Index_" + new Integer(i + 1).toString() + ":");// 将ScanResult信息转换成一个字符串包  // 其中把包括：BSSID、SSID、capabilities、frequency、level  sb.append((mWifiList.get(i)).toString()).append("\n");}return sb;    }public String getMacAddress(){return (mWifiInfo==null)?"NULL":mWifiInfo.getMacAddress();}public String getBSSID(){return (mWifiInfo==null)?"NULL":mWifiInfo.getBSSID();}public int getIpAddress(){return (mWifiInfo==null)?0:mWifiInfo.getIpAddress();}//得到连接的IDpublic int getNetWordId(){return (mWifiInfo==null)?0:mWifiInfo.getNetworkId();}//得到wifiInfo的所有信息public String getWifiInfo(){return (mWifiInfo==null)?"NULL":mWifiInfo.toString();}//添加一个网络并连接public void addNetWork(WifiConfiguration configuration){int wcgId=mWifiManager.addNetwork(configuration);mWifiManager.enableNetwork(wcgId, true);}//断开指定ID的网络public void disConnectionWifi(int netId){mWifiManager.disableNetwork(netId);mWifiManager.disconnect();}
}

import java.util.List;import android.app.Activity;
import android.net.wifi.ScanResult;
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 WifiActivity extends Activity {/** Called when the activity is first created. */private TextView allNetWork;  private Button scan;  private Button start;  private Button stop;  private Button check;  private WifiAdmin mWifiAdmin;  // 扫描结果列表  private List<ScanResult> list;  private ScanResult mScanResult;  private StringBuffer sb=new StringBuffer();  @Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);mWifiAdmin = new WifiAdmin(WifiActivity.this);  init();  }public void init(){allNetWork = (TextView) findViewById(R.id.allNetWork);  scan = (Button) findViewById(R.id.scan);  start = (Button) findViewById(R.id.start);  stop = (Button) findViewById(R.id.stop);  check = (Button) findViewById(R.id.check); scan.setOnClickListener(new MyListener());  start.setOnClickListener(new MyListener());  stop.setOnClickListener(new MyListener());  check.setOnClickListener(new MyListener());  }private class MyListener implements OnClickListener{@Overridepublic void onClick(View v) {// TODO Auto-generated method stubswitch (v.getId()) {case R.id.scan://扫描网络
                  getAllNetWorkList();  break;case R.id.start://打开Wifi
                mWifiAdmin.openWifi();Toast.makeText(WifiActivity.this, "当前wifi状态为："+mWifiAdmin.checkState(), 1).show();break;case R.id.stop://关闭Wifi
                mWifiAdmin.closeWifi();Toast.makeText(WifiActivity.this, "当前wifi状态为："+mWifiAdmin.checkState(), 1).show();break;case R.id.check://Wifi状态Toast.makeText(WifiActivity.this, "当前wifi状态为："+mWifiAdmin.checkState(), 1).show();break;default:break;}}}public void getAllNetWorkList(){// 每次点击扫描之前清空上一次的扫描结果  if(sb!=null){sb=new StringBuffer();}//开始扫描网络
        mWifiAdmin.startScan();list=mWifiAdmin.getWifiList();if(list!=null){for(int i=0;i<list.size();i++){//得到扫描结果mScanResult=list.get(i);sb=sb.append(mScanResult.BSSID+"  ").append(mScanResult.SSID+"   ").append(mScanResult.capabilities+"   ").append(mScanResult.frequency+"   ").append(mScanResult.level+"\n\n");}allNetWork.setText("扫描到的wifi网络：\n"+sb.toString());}}
}

   <!-- 以下是使用wifi访问网络所需的权限 -->  <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission>  <uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission>  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>  <uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>