微信公眾號支付 請求跳轉code跨域

1.開發(fā)微信商城公眾號支付，前端發(fā)起ajax請求到服務器初始化訂單。之后由服務器獲取openid之后發(fā)起支付。在獲取openid的第一步出現(xiàn)跨域異常。一下是部分代碼：

header('Access-Control-Allow-Origin: *');
header('Content-type:text/html; Charset=utf-8');
header("Access-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept");
header('Access-Control-Allow-Methods: GET, POST, PUT,DELETE');
$mchid = '123456789622';          //微信支付商戶號 PartnerID 通過微信支付商戶資料審核后郵件發(fā)送
$appid = 'dsalkdfjkldjsf154';  //微信支付申請對應的公眾號的APPID
$appKey = '43das153d43as5';   //微信支付申請對應的公眾號的APP Key
$apiKey = 'as4das5d745as7d6a7';   //https://pay.weixin.qq.com 帳戶設置-安全設置-API安全-API密鑰-設置API密鑰
//①、獲取用戶openid
$wxPay = new WxpayService($mchid, $appid, $appKey, $apiKey);
$openId = $wxPay->GetOpenid();      //獲取openid
if (!$openId) exit('獲取openid失敗');
--------------在這里處理業(yè)務------------------
$input = @file_get_contents('php://input');
$requestArr = json_decode($input, true);
if (empty($requestArr)) {
    echo "請求數(shù)據(jù)為空";
    return;
}
//略
-----------------
class WxpayService
{
    protected $mchid;
    protected $appid;
    protected $appKey;
    protected $apiKey;
    public $data = null;

    public function __construct($mchid, $appid, $appKey, $key)
    {
        $this->mchid = $mchid; //https://pay.weixin.qq.com 產(chǎn)品中心-開發(fā)配置-商戶號
        $this->appid = $appid; //微信支付申請對應的公眾號的APPID
        $this->appKey = $appKey; //微信支付申請對應的公眾號的APP Key
        $this->apiKey = $key;   //https://pay.weixin.qq.com 帳戶設置-安全設置-API安全-API密鑰-設置API密鑰
    }

    /**
     * 通過跳轉獲取用戶的openid，跳轉流程如下：
     * 1、設置自己需要調(diào)回的url及其其他參數(shù)，跳轉到微信服務器https://open.weixin.qq.com/connect/oauth2/authorize
     * 2、微信服務處理完成之后會跳轉回用戶redirect_uri地址，此時會帶上一些參數(shù)，如：code
     * @return 用戶的openid
     */
    public function GetOpenid()
    {
        //通過code獲得openid
        if (!isset($_GET['code'])) {
            //觸發(fā)微信返回code碼
            $scheme = $_SERVER['HTTPS'] == 'on' ? 'https://' : 'http://';
            $baseUrl = urlencode($scheme . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'] . $_SERVER['QUERY_STRING']);
            $url = $this->__CreateOauthUrlForCode($baseUrl);
            Header("Location: $url");
            exit();
        } else {
            //獲取code碼，以獲取openid
            $code = $_GET['code'];
            $openid = $this->getOpenidFromMp($code);
            return $openid;
        }
    }

    /**
     * 通過code從工作平臺獲取openid機器access_token
     * @param string $code 微信跳轉回來帶上的code
     * @return openid
     */
    public function GetOpenidFromMp($code)
    {
        $url = $this->__CreateOauthUrlForOpenid($code);
        $res = self::curlGet($url);
        //取出openid
        $data = json_decode($res, true);
        $this->data = $data;
        $openid = $data['openid'];
        return $openid;
    }

    /**
     * 構造獲取open和access_toke的url地址
     * @param string $code，微信跳轉帶回的code
     * @return 請求的url
     */
    private function __CreateOauthUrlForOpenid($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;
    }

    /**
     * 構造獲取code的url連接
     * @param string $redirectUrl 微信服務器回跳的url，需要url編碼
     * @return 返回構造好的url
     */
    private function __CreateOauthUrlForCode($redirectUrl)
    {
        $urlObj["appid"] = $this->appid;
        $urlObj["redirect_uri"] = "$redirectUrl";
        $urlObj["response_type"] = "code";
        $urlObj["scope"] = "snsapi_base";
        $urlObj["state"] = "STATE" . "#wechat_redirect";
        $bizString = $this->ToUrlParams($urlObj);
        return "https://open.weixin.qq.com/connect/oauth2/authorize?" . $bizString;
    }

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

    /**
     * 統(tǒng)一下單
     * @param string $openid 調(diào)用【網(wǎng)頁授權獲取用戶信息】接口獲取到用戶在該公眾號下的Openid
     * @param float $totalFee 收款總費用 單位元
     * @param string $outTradeNo 唯一的訂單號
     * @param string $orderName 訂單名稱
     * @param string $notifyUrl 支付結果通知url 不要有問號
     * @param string $timestamp 支付時間
     * @return string
     */
    public function createJsBizPackage($openid, $totalFee, $outTradeNo, $orderName, $notifyUrl, $timestamp)
    {
        $config = array(
            'mch_id' => $this->mchid,
            'appid' => $this->appid,
            'key' => $this->apiKey,
        );
        $orderName = iconv('GBK', 'UTF-8', $orderName);
        $unified = array(
            'appid' => $config['appid'],
            'attach' => 'pay',             //商家數(shù)據(jù)包，原樣返回，如果填寫中文，請注意轉換為utf-8
            'body' => $orderName,
            'mch_id' => $config['mch_id'],
            'nonce_str' => self::createNonceStr(),
            'notify_url' => $notifyUrl,
            'openid' => $openid,            //rade_type=JSAPI，此參數(shù)必傳
            'out_trade_no' => $outTradeNo,
            'spbill_create_ip' => '127.0.0.1',
            'total_fee' => intval($totalFee * 100),       //單位 轉為分
            'trade_type' => 'JSAPI',
        );
        $unified['sign'] = self::getSign($unified, $config['key']);
        $responseXml = self::curlPost('https://api.mch.weixin.qq.com/pay/unifiedorder', self::arrayToXml($unified));
        $unifiedOrder = simplexml_load_string($responseXml, 'SimpleXMLElement', LIBXML_NOCDATA);
        if ($unifiedOrder === false) {
            die('parse xml error');
        }
        if ($unifiedOrder->return_code != 'SUCCESS') {
            die($unifiedOrder->return_msg);
        }
        if ($unifiedOrder->result_code != 'SUCCESS') {
            die($unifiedOrder->err_code);
        }
        $arr = array(
            "appId" => $config['appid'],
            "timeStamp" => "$timestamp",        //這里是字符串的時間戳，不是int，所以需加引號
            "nonceStr" => self::createNonceStr(),
            "package" => "prepay_id=" . $unifiedOrder->prepay_id,
            "signType" => 'MD5',
        );
        $arr['paySign'] = self::getSign($arr, $config['key']);
        return $arr;
    }

    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, $options);
        }
        //https請求 不驗證證書和host
        curl_setopt($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); //設置cURL允許執(zhí)行的最長秒數(shù)
        if (!empty($options)) {
            curl_setopt_array($ch, $options);
        }
        //https請求 不驗證證書和host
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $data = curl_exec($ch);
        curl_close($ch);
        return $data;
    }

    public static function createNonceStr($length = 16)
    {
        $chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        $str = '';
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    public static function arrayToXml($arr)
    {
        $xml = "<xml>";
        foreach ($arr as $key => $val) {
            if (is_numeric($val)) {
                $xml .= "<" . $key . ">" . $val . "</" . $key . ">";
            } else
                $xml .= "<" . $key . "><![CDATA[" . $val . "]]></" . $key . ">";
        }
        $xml .= "</xml>";
        return $xml;
    }

    public static function getSign($params, $key)
    {
        ksort($params, SORT_STRING);
        $unSignParaString = self::formatQueryParaMap($params, false);
        $signStr = strtoupper(md5($unSignParaString . "&key=" . $key));
        return $signStr;
    }

    protected static function formatQueryParaMap($paraMap, $urlEncode = false)
    {
        $buff = "";
        ksort($paraMap);
        foreach ($paraMap as $k => $v) {
            if (null != $v && "null" != $v) {
                if ($urlEncode) {
                    $v = urlencode($v);
                }
                $buff .= $k . "=" . $v . "&";
            }
        }
        $reqPar = '';
        if (strlen($buff) > 0) {
            $reqPar = substr($buff, 0, strlen($buff) - 1);
        }
        return $reqPar;
    }
}

3.XMLHttpRequest cannot load https://open.weixin.qq.com/co... Response for preflight is invalid (redirect)
現(xiàn)在差不多可以定位在Header("Location: $url");這里出現(xiàn)的錯誤了。搜了一圈還是沒結果。。。
4.這個幾乎就是官方demo加上業(yè)務邏輯而已