/** 
 * make true current connect service is wifi 
 * @param mContext 
 * @return 
 */  
private static boolean isWifi(Context mContext) {  
    ConnectivityManager connectivityManager = (ConnectivityManager) mContext  
            .getSystemService(Context.CONNECTIVITY_SERVICE);  
    NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();  
    if (activeNetInfo != null  
            && activeNetInfo.getType() == ConnectivityManager.TYPE_WIFI) {  
        return true;  
    }  
    return false;  
}