连接Wifi

public interface ScanWiFIScanListener {
    void scanList(List<INfo> list);
}



public class INfo {
    String ssid;//
    String capabilities;//
    String bssid;//
    int level;//信号强度-20到0是最强的
    public String getSsid() {
        return ssid;
    }
    public void setSsid(String ssid) {
        this.ssid = ssid;
    }
    public String getCapabilities() {
        return capabilities;
    }
    public void setCapabilities(String capabilities) {
        this.capabilities = capabilities;
    }
    public String getBssid() {
        return bssid;
    }
    public void setBssid(String bssid) {
        this.bssid = bssid;
    }
    public int getLevel() {
        return level;
    }
    public void setLevel(int level) {
        this.level = level;
    }
    @Override
    public String toString() {
        return "INfo [ssid=" + ssid + ", capabilities=" + capabilities
                + ", bssid=" + bssid + ", level=" + level + "]";
    }

}



public class MyB extends BroadcastReceiver{
    WifiManager wifiManager;
    ScanWiFIScanListener listener;//传到activity那边
    
    public ScanWiFIScanListener getListener() {
        return listener;
    }

    public void setListener(ScanWiFIScanListener listener) {
        this.listener = listener;
    }

    //拿到收到的wifi
    public MyB(WifiManager wifiManager) {
        super();
        this.wifiManager = wifiManager;
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        Log.i("INFO", "wifi is founded");
        //动态注册，代码注册
        //通过意图拿
        List<ScanResult> list= wifiManager.getScanResults();
        List<INfo> infos=new ArrayList<INfo>();
        for (ScanResult scanResult : list) {
            Log.i("INFO", scanResult.SSID);
            //没每个实体赋值添加到集合
            INfo info=new INfo();
            info.setBssid(scanResult.BSSID);
            info.setCapabilities(scanResult.capabilities);
            info.setLevel(scanResult.level);
            
            infos.add(info);
        }
        //蓝牙是异步扫描，wifi是同步扫描，一下子扫到
        listener.scanList(infos);
    
    }

}



@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        LayoutInflater inflater=(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View vv=inflater.inflate(R.layout.list_item, null);
        TextView tv_ssid=(TextView) vv.findViewById(R.id.tv_ssid);
        TextView tv_bbid=(TextView) vv.findViewById(R.id.tv_bbid);
        TextView tv_p=(TextView) vv.findViewById(R.id.tv_p);
        ImageView iv_level=(ImageView) vv.findViewById(R.id.iv_level);
        iNfo=list.get(position);
        
        tv_ssid.setText(iNfo.getSsid());
        tv_bbid.setText(iNfo.getBssid());
        tv_p.setText(iNfo.getCapabilities());
        
        //判断level在那个区间
        //drawable
        int level = iNfo.getLevel();
        iv_level.setImageResource(R.drawable.image_level);
        if(-100<level&&level<-80){
            iv_level.setImageLevel(0);
        }else if(level<-60){
            iv_level.setImageLevel(1);
        }else if(level<-40){
            iv_level.setImageLevel(2);
        }else if(level<-20){
            iv_level.setImageLevel(3);
        }else{
            iv_level.setImageLevel(4);
        }
        
        //img.setImageLevel(0);
        return vv;
    }



public class MainActivity extends Activity implements ScanWiFIScanListener {
    ListView lv;
    MyB b;
    WifiManager wifiManager;
    MyAdapter adapter;
    List<INfo> list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lv = (ListView) findViewById(R.id.lv);
        wifiManager = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);
        b = new MyB(wifiManager);
        b.setListener(this);//
        List<INfo> list = new ArrayList<INfo>();
        adapter = new MyAdapter(this, list);
        lv.setAdapter(adapter);
    }

    public void scanwifi(View v) {
        if (!wifiManager.isWifiEnabled()) {// 是否可用
            wifiManager.setWifiEnabled(true);// 打开
        }
        wifiManager.startScan();// 开始扫描
        // 注册广播
        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);// 扫描结果可用，可拿到
        this.registerReceiver(b, intentFilter);
        // 扫描到就放进去
        adapter.getList().clear();
        adapter.notifyDataSetChanged();
    }

    @Override
    public void scanList(List<INfo> list) {
        // TODO Auto-generated method stub
        // 设置给adapter,刷新listView
        adapter.setList(list);
        adapter.notifyDataSetChanged();
    }

}