使用php实现微信登录其实并不难，可以简单地分为三步进行。

第一步：用户同意授权，获取code

//微信登录public function wxlogin(){$appid = "";$secret = "";$str="http://***.***.com/getToken";$redirect_uri=urlencode($str);//通过code获得 access_token + openid$url="https://open.weixin.qq.com/connect/oauth2/authorize?appid=".$appid."&redirect_uri=".$redirect_uri."&response_type=code&scope=snsapi_userinfo&state=STATE#wechat_redirect";header("Location:" . $url);}

第二步：通过code换取网页授权access_token

public function getToken(){$code = $_GET["code"];$appid = "";$secret = "";//通过code获得 access_token + openid$url="https://api.weixin.qq.com/sns/oauth2/access_token?appid=".$appid."&secret=" . $secret . "&code=" . $code . "&grant_type=authorization_code";$jsonResult =$this->https_request($url);$resultArray = json_decode($jsonResult, true);$access_token = $resultArray["access_token"];$openid = $resultArray["openid"];//第三步  获取用户信息//通过access_token + openid 获得用户所有信息,结果全部存储在$infoArray里,后面再写自己的代码逻辑$infoUrl = "https://api.weixin.qq.com/sns/userinfo?access_token=" . $access_token . "&openid=" . $openid.'&lang=zh_CN';$infoResult = $this->https_request($infoUrl);$infoArray = json_decode($infoResult, true);if($infoArray['unionid']){}}

附加：代码中用到的方法 

// An highlighted blockfunction https_request($url, $data = null){$curl = curl_init();curl_setopt($curl, CURLOPT_URL, $url);curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);if (!empty($data)){curl_setopt($curl, CURLOPT_POST, 1);curl_setopt($curl, CURLOPT_POSTFIELDS, $data);}curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);$output = curl_exec($curl);curl_close($curl);return $output;}