最近做WiFi方面需求，遇到一個問題就是連線掃描的的熱點總是連線不上（不經加密的），程式碼如下：

    /*連線到熱點*/
    public void connectToHotpot(){
        List<ScanResult> results = mWifiManager.getScanResults();
        for (ScanResult result : results){
            if (result.SSID.contains("zeus")){
                WifiConfiguration wifiConfig = new WifiConfiguration();
                wifiConfig.SSID = result.SSID;
                int wcgID = mWifiManager.addNetwork(wifiConfig);
                mWifiManager.enableNetwork(wcgID, true);
                break;
            }
        }

    }
 

先獲取一下附近WiFi列表，如果是需要連線的WiFi，就去連線，但是執行了mWifiManager.enableNetwork(wcgID, true);這句話以後並沒有連線上，（手動連線一次以後就可以自動連線了），後來在帖子上看到了答案，正確程式碼如下：

    /*連線到熱點*/
    public void connectToHotpot(){
        List<ScanResult> results = mWifiManager.getScanResults();
        for (ScanResult result : results){
            if (result.SSID.contains("zeus")){
                WifiConfiguration wifiConfig = new WifiConfiguration();
                wifiConfig.SSID = result.SSID;
                wifiConfig.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
                wifiConfig.wepTxKeyIndex = 0;
 

                int wcgID = mWifiManager.addNetwork(wifiConfig);
                mWifiManager.enableNetwork(wcgID, true);
                break;
            }
        }

    }

因為當時建立熱點是不加密的，也就是開放的，這裡enableNetwork的時候也需要去明確一下加密方式為none，原始碼中WiFi的加密方式有以下幾種：

 /** WPA is not used; plaintext or static WEP could be used. */
        public static final int NONE = 0;
 

        /** WPA pre-shared key (requires {@code preSharedKey} to be specified). */
        public static final int WPA_PSK = 1;
        /** WPA using EAP authentication. Generally used with an external authentication server. */
        public static final int WPA_EAP = 2;
        /** IEEE 802.1X using EAP authentication and (optionally) dynamically
         * generated WEP keys. */
        public static final int IEEE8021X = 3;

        /** WPA2 pre-shared key for use with soft access point
          * (requires {@code preSharedKey} to be specified).
          * @hide
          */
        public static final int WPA2_PSK = 4;

下面是建立熱點的程式碼：

 /** set WiFi hot spot is enableed */
    private boolean setWifiApEnabled(WifiConfiguration configuration, boolean enabled)
    {
        try
        {
            if (enabled)
            {
                mWifiManager.setWifiEnabled(false);
            }

            Method method = mWifiManager.getClass().getMethod("setWifiApEnabled",
                WifiConfiguration.class, boolean.class);
            return (Boolean) method.invoke(mWifiManager, configuration, enabled);
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }

        return false;
    }

開啟熱點是需要反射的，因為setWifiApEnable方法在原始碼中是@hide的，目前並不對外開放：

    /**
     * Start AccessPoint mode with the specified
     * configuration. If the radio is already running in
     * AP mode, update the new configuration
     * Note that starting in access point mode disables station
     * mode operation
     * @param wifiConfig SSID, security and channel details as
     *        part of WifiConfiguration
     * @return {@code true} if the operation succeeds, {@code false} otherwise
     *
     * @hide Dont open up yet
     */
    public boolean setWifiApEnabled(WifiConfiguration wifiConfig, boolean enabled) {
        try {
            mService.setWifiApEnabled(wifiConfig, enabled);
            return true;
        } catch (RemoteException e) {
            return false;
        }
    }

但是，好像是有個例外，htc的手機開啟熱點需要特殊處理一下：

 /** enable and disable htc WiFi hotspot, 2013-12-31 add special for htc */
    private boolean enableHtcHotspot(WifiConfiguration apConfig, boolean enable)
    {

        Method method = null;
        try
        {
            method = mWifiManager.getClass().getMethod("setWifiApEnabled",
                WifiConfiguration.class, Boolean.TYPE);
        }
        catch (NoSuchMethodException e)
        {
            e.printStackTrace();
        }
        // 返回熱點開啟狀態
        boolean flag = false;
        try
        {
            flag = (Boolean) method.invoke(mWifiManager, apConfig, enable);
        }
        catch (IllegalArgumentException e)
        {
            flag = false;
            e.printStackTrace();
        }
        catch (IllegalAccessException e)
        {
            flag = false;
            e.printStackTrace();
        }
        catch (InvocationTargetException e)
        {
            flag = false;
            e.printStackTrace();
        }

        return flag;
    }

因為也是初次接觸WiFi方面，所以遇到的問題比較多，需要注意的點：

1、加密方式，連線的時候一定要明確建立熱點時使用的加密方式。

2、注意熱點和WiFi是不能同時開的。

以上是自己遇到的坑，記錄一下，關於WiFi這塊週末研究一下。