Android检测网络是否可用并打开、扫描、连接WIFI

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>  
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"></uses-permission><!-- 允许程序改变网络链接状态 -->  
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission><!--允许程序访问访问WIFI网络状态信息  -->  
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"></uses-permission><!-- 允许程序改变WIFI链接状态 --> 

    public boolean netWorkIsEnable() {
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        try {
            // 通过ping百度检测网络是否可用
            Process p = Runtime.getRuntime().exec("/system/bin/ping -c " + 1 + " 202.108.22.5");
            int status = p.waitFor(); // 只有0时表示正常返回
            return (connectivityManager.getActiveNetworkInfo() != null && status == 0);
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        } catch (InterruptedException e) {
            e.printStackTrace();
            return false;
        }

    }

	private void initWifiState() {
        wifiManager = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);
        if (!wifiManager.isWifiEnabled()) {
            wifiManager.setWifiEnabled(true);
        }
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                wifiManager.startScan();
                scanResults = wifiManager.getScanResults();
                if (scanResults != null && scanResults.size() > 0) {
                    wifiListAdapter = new WifiListAdapter(mContext, scanResults);
                    lvWifiSignal.setAdapter(wifiListAdapter);
                } else {
                    Toast.makeText(InitSettingActivity.this, "没有搜索到可用网络", Toast.LENGTH_SHORT).show();
                }
            }
        }, 6000);

    }

private void toConnectWifi() {
        ScanResult result = scanResults.get(currentPosition);
        String ssid = result.SSID;
        String pwd = etWifiPwd.getText().toString().trim();
        Log.e("TAG", "pwd=" + pwd);
        if (null == pwd || pwd.length() < 8) {
            Toast.makeText(InitSettingActivity.this, "密码至少为8位", Toast.LENGTH_SHORT).show();
            return;
        }

		int wcgID = mWifiManager.addNetwork(CreateWifiInfo(ssid, pwd, 3));
        boolean b = mWifiManager.enableNetwork(wcgID, true);
    }

// 创建wifi配置对象
public WifiConfiguration CreateWifiInfo(String SSID, String Password, int Type) {
        WifiConfiguration config = new WifiConfiguration();
        config.allowedAuthAlgorithms.clear();
        config.allowedGroupCiphers.clear();
        config.allowedKeyManagement.clear();
        config.allowedPairwiseCiphers.clear();
        config.allowedProtocols.clear();
        config.SSID = "\"" + SSID + "\"";

        WifiConfiguration tempConfig = this.IsExsits(SSID);
        if (tempConfig != null) {
            mWifiManager.removeNetwork(tempConfig.networkId);
        }

        if (Type == 1) //WIFICIPHER_NOPASS
        {
            config.wepKeys[0] = "";
            config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
            config.wepTxKeyIndex = 0;
        }
        if (Type == 2) //WIFICIPHER_WEP
        {
            config.hiddenSSID = true;
            config.wepKeys[0] = "\"" + Password + "\"";
            config.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.SHARED);
            config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
            config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
            config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
            config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
            config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
            config.wepTxKeyIndex = 0;
        }
        if (Type == 3) //WIFICIPHER_WPA
        {
            config.preSharedKey = "\"" + Password + "\"";
            config.hiddenSSID = true;
            config.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
            config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
            config.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
            config.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
//            config.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
            config.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
            config.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
            config.status = WifiConfiguration.Status.ENABLED;
        }
        return config;
    }

/**
     * 监听wifi状态变化的广播接收器
     */
    private BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

            NetworkInfo wifiInfo = manager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
            if (wifiInfo.isConnected()) {
                WifiManager wifiManager = (WifiManager) context
                        .getSystemService(Context.WIFI_SERVICE);
                String wifiSSID = wifiManager.getConnectionInfo().getSSID();
                llShow.setVisibility(View.GONE);
                tvToast1.setVisibility(View.VISIBLE);
                tvToast1.setText(R.string.init_door_equipment08);
                handler.sendEmptyMessageDelayed(1, 3000);

            } else if (wifiInfo.isConnectedOrConnecting()) {
                llShow.setVisibility(View.GONE);
                tvToast1.setVisibility(View.VISIBLE);
                tvToast1.setText(R.string.init_door_equipment05);

            } else if (wifiInfo.isFailover()) {
                llShow.setVisibility(View.GONE);
                tvToast1.setVisibility(View.VISIBLE);
                tvToast1.setText(R.string.init_door_equipment06);
            }
        }
    };

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_init_setting);
        mContext = this;

        // 取得WifiManager对象
        mWifiManager = (WifiManager) context
                .getSystemService(Context.WIFI_SERVICE);
        // 取得WifiInfo对象
        mWifiInfo = mWifiManager.getConnectionInfo();

        IntentFilter filter = new IntentFilter(
                WifiManager.NETWORK_STATE_CHANGED_ACTION);
        registerReceiver(mReceiver, filter);
    }

@Override
    protected void onDestroy() {
        super.onDestroy();
        unregisterReceiver(mReceiver);
    }