今天来点干货，讲讲如何通过代码连接上指定的wifi。相当于使用代码完成使用者在手机WLAN中选择wifi,并且输入密码，然后点击确定的过程。

既然要操纵wifi，就需要使用到wifiManager，我们连接过的wifi的名称和密码都可以通过WifiManger来拿到，每个信息都是封装到一个ScanResult的类中，然后放到列表中的。

     WifiManager mWifiManager = (WifiManager) getSystemService(WIFI_SERVICE);

1 如何获取已经连接过的wifi信息

    mWifiManager.startScan();
    mWifiList = mWifiManager.getScanResults();
    mWificonfiguration = mWifiManager.getConfiguredNetworks();

2 去连接以前连接过的wifi

    mWifiManager.enableNetwork(index, true);
    其中的index是netWorkId,就是存在上面的list（mWificonfiguration）中的，目前获取networkId只能去列表中获取。

3获取networkId

    int networkId = mWificonfiguration.get（index）.networkId;
    其中的index,需要自己确定

4上面都是讲的连接以前连过的，现在说如何连接从来没有连接过的wifi.上面都是从列表信息中拿到了networkId,现在从来没有连接过的wifi怎么获取networId呢？我们可以创建一个wifi的信息，然后添加到wifiManager中去，然后再获取networkId，就ok了。

    public WifiConfiguration createWifiInfo(String SSID, String Password, int Type) {
    WifiConfiguration configuration = new WifiConfiguration();
    configuration.allowedAuthAlgorithms.clear();
    configuration.allowedGroupCiphers.clear();
    configuration.allowedKeyManagement.clear();
    configuration.allowedPairwiseCiphers.clear();
    configuration.allowedProtocols.clear();
    configuration.SSID = "\"" + SSID + "\"";

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

    switch (Type) {
        case 1://不加密
            configuration.wepKeys[0] = "";
            configuration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
            configuration.wepTxKeyIndex = 0;
            configuration.priority= 20000;
            break;
        case 2://wep加密
            configuration.hiddenSSID = true;
            configuration.wepKeys[0] = "\"" + Password +"\"";
            configuration.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.SHARED);
            configuration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
            configuration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
            configuration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
            configuration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
            configuration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);

            break;
        case 3: //wpa加密

            configuration.preSharedKey = "\"" + Password + "\"";
            configuration.hiddenSSID = true;
            configuration.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
            configuration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
            configuration.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
            configuration.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
            configuration.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
            configuration.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
            configuration.status = WifiConfiguration.Status.ENABLED;
            break;
    }
    return  configuration;
}

    上面是创建wifi配置信息，下面是添加


    int networkId = mWifiManager.addNetwork(wifiConfiguration);

比如关掉wifi这一类的方法我也就不在这里多说了，上面的方法我已经封装成了工具类。 
源码地址：https://github.com/Blowing/AutoConnectWifi