微信登录功能的实现直接复制就能使用（封装）

//使用
session_start();
$wids = $_SESSION["cxuid"];
$winame = $_SESSION["cxname"];
$wiimg = $_SESSION["cximg"];
if (!$_SESSION["cxuid"]) { //是否重新获取
    error_reporting(1);
    header('Content-type:text/html; Charset=utf-8');
    /* 配置开始 */
    $appid = '';  //微信公众平台->开发->基本配置->AppID
    $appKey = '';   //微信公众平台->开发->基本配置->AppSecret
    /* 配置结束 */
    //echo "222";
    //①、获取用户openid
    $wxPay = new WxService($appid, $appKey);
    $data = $wxPay->GetOpenid();      //获取openid
    $user = $wxPay->getUserInfo($data['openid'], $data['access_token']);
    if (!$data['openid'])  exit('获取openid失败');
    $wids = $user['openid'];
    $_SESSION["cxuid"] = $user['openid'];
    $_SESSION["cxname"] = $user['nickname'];
    $_SESSION["cximg"] = $user['headimgurl'];
}
//打印出数据
print_r($_SESSION);



class WxService
{
    protected $appid;
    protected $appKey;

    public $data = null;

    public function __construct($appid, $appKey)
    {
        $this->appid = $appid; //微信支付申请对应的公众号的APPID
        $this->appKey = $appKey; //微信支付申请对应的公众号的APP Key
    }

    /**
     * 通过跳转获取用户的openid，跳转流程如下：
     * 1、设置自己需要调回的url及其其他参数，跳转到微信服务器https://open.weixin.qq.com/connect/oauth2/authorize
     * 2、微信服务处理完成之后会跳转回用户redirect_uri地址，此时会带上一些参数，如：code
     *
     * @return 用户的openid
     */
    public function GetOpenid()
    {
        //通过code获得openid
        if (!isset($_GET['code'])){
            //触发微信返回code码
            $baseUrl = $this->getCurrentUrl();
            $url = $this->__CreateOauthUrlForCode($baseUrl);
            Header("Location: $url");
            exit();
        } else {
            //获取code码，以获取openid
            $code = $_GET['code'];
            $openid = $this->getOpenidFromMp($code);
            return $openid;
        }
    }

    public function getCurrentUrl()
    {
        $scheme = $_SERVER['HTTPS']=='on' ? 'https://' : 'http://';
        $uri = $_SERVER['PHP_SELF'].$_SERVER['QUERY_STRING'];
        if($_SERVER['REQUEST_URI']) $uri = $_SERVER['REQUEST_URI'];
        $baseUrl = urlencode($scheme.$_SERVER['HTTP_HOST'].$uri);
        return $baseUrl;
    }

    /**
     * 通过code从工作平台获取openid机器access_token
     * @param string $code 微信跳转回来带上的code
     * @return openid
     */
    public function GetOpenidFromMp($code)
    {
        $url = $this->__CreateOauthUrlForOpenid($code);        
        $res = self::curlGet($url);
        $data = json_decode($res,true);
        $this->data = $data;
        return $data;
    }

    /**
     * 构造获取open和access_toke的url地址
     * @param string $code，微信跳转带回的code
     * @return 请求的url
     */
    private function __CreateOauthUrlForOpenid($code)
    {
        $urlObj["appid"] = $this->appid;
        $urlObj["secret"] = $this->appKey;
        $urlObj["code"] = $code;
        $urlObj["grant_type"] = "authorization_code";
        $bizString = $this->ToUrlParams($urlObj);
        return "https://api.weixin.qq.com/sns/oauth2/access_token?".$bizString;
    }

    /**
     * 构造获取code的url连接
     * @param string $redirectUrl 微信服务器回跳的url，需要url编码
     * @return 返回构造好的url
     */
    private function __CreateOauthUrlForCode($redirectUrl)
    {
        $urlObj["appid"] = $this->appid;
        $urlObj["redirect_uri"] = "$redirectUrl";
        $urlObj["response_type"] = "code";
        $urlObj["scope"] = "snsapi_userinfo";
        $urlObj["state"] = "STATE";
        $bizString = $this->ToUrlParams($urlObj);
        return "https://open.weixin.qq.com/connect/oauth2/authorize?".$bizString;
    }

    /**
     * 拼接签名字符串
     * @param array $urlObj
     * @return 返回已经拼接好的字符串
     */
    private function ToUrlParams($urlObj)
    {
        $buff = "";
        foreach ($urlObj as $k => $v)
        {
            if($k != "sign") $buff .= $k . "=" . $v . "&";
        }
        $buff = trim($buff, "&");
        return $buff;
    }

    /**
     * 获取用户信息
     * @param string $openid 调用【网页授权获取用户信息】接口获取到用户在该公众号下的Openid
     * @return string
     */
    public function getUserInfo($openid,$access_token)
    {

        $response = self::curlGet('https://api.weixin.qq.com/sns/userinfo?access_token='.$access_token.'&openid='.$openid.'&lang=zh_CN');
        return json_decode($response,true);
        
    }

    public static function curlGet($url = '', $options = array())
    {
        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30);
        if (!empty($options)) {
            curl_setopt_array($ch, $options);
        }
        //https请求 不验证证书和host
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $data = curl_exec($ch);
        curl_close($ch);
        return $data;
    }

    public static function curlPost($url = '', $postData = '', $options = array())
    {
        if (is_array($postData)) {
            $postData = http_build_query($postData);
        }
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $postData);
        curl_setopt($ch, CURLOPT_TIMEOUT, 30); //设置cURL允许执行的最长秒数
        if (!empty($options)) {
            curl_setopt_array($ch, $options);
        }
        //https请求 不验证证书和host
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $data = curl_exec($ch);
        curl_close($ch);
        return $data;
    }

}