摘要：直接運行該文件即可得到一個支付二維碼的圖片。需要注意的事項該文件需放到支付授權目錄下，可以在微信支付商戶平臺產品中心開發配置中設置。

網上的很多PHP微信掃碼支付接入教程都頗為復雜，且需要配置和引入較多的文件，本人通過整理后給出一個單文件版的，只有200行代碼，希望可以給各位想接入微信掃碼支付的帶來些許幫助和借鑒意義。

直接運行該文件即可得到一個支付二維碼的圖片。

需要注意的事項：
1.該文件需放到支付授權目錄下，可以在微信支付商戶平臺->產品中心->開發配置中設置。
2.如提示簽名錯誤可以通過微信支付簽名驗證工具進行驗證：https://pay.weixin.qq.com/wik...

代碼如下：

createJsBizPackage($payAmount,$outTradeNo,$orderName,$notifyUrl,$payTime);
//生成二維碼
$url = "http://qr.liantu.com/api.php?text=".$arr["code_url"];
echo "";

class WxpayService
{
    protected $mchid;
    protected $appid;
    protected $apiKey;

    public function __construct($mchid, $appid, $key)
    {
        $this->mchid = $mchid;
        $this->appid = $appid;
        $this->apiKey = $key;
    }

    /**
     * 發起訂單
     * @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 $timestamp 訂單發起時間
     * @return array
     */
    public function createJsBizPackage($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",             //商家數據包，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,
            "out_trade_no" => $outTradeNo,
            "spbill_create_ip" => "127.0.0.1",
            "total_fee" => intval($totalFee * 100),       //單位 轉為分
            "trade_type" => "NATIVE",
        );
        $unified["sign"] = self::getSign($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);
        }
        $codeUrl = (array)($unifiedOrder->code_url);
        if(!$codeUrl[0]) exit("get code_url error");
        $arr = array(
            "appId" => $config["appid"],
            "timeStamp" => $timestamp,
            "nonceStr" => self::createNonceStr(),
            "package" => "prepay_id=" . $unifiedOrder->prepay_id,
            "signType" => "MD5",
            "code_url" => $codeUrl[0],
        );
        $arr["paySign"] = self::getSign($arr, $config["key"]);
        return $arr;
    }


    public function notify()
    {
        $config = array(
            "mch_id" => $this->mchid,
            "appid" => $this->appid,
            "key" => $this->apiKey,
        );
        $postStr = $GLOBALS["HTTP_RAW_POST_DATA"];

        $postObj = simplexml_load_string($postStr, "SimpleXMLElement", LIBXML_NOCDATA);
        if ($postObj === false) {
            die("parse xml error");
        }
        if ($postObj->return_code != "SUCCESS") {
            die($postObj->return_msg);
        }
        if ($postObj->result_code != "SUCCESS") {
            die($postObj->err_code);
        }
        $arr = (array)$postObj;
        unset($arr["sign"]);
        if (self::getSign($arr, $config["key"]) == $postObj->sign) {
            echo "";
            return $postObj;
        }
    }

    /**
     * curl get
     *
     * @param string $url
     * @param array $options
     * @return mixed
     */
    public static function curlGet($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允許執行的最長秒數
        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)
    {
        $xml = "";
        foreach ($arr as $key => $val) {
            if (is_numeric($val)) {
                $xml .= "<" . $key . ">" . $val . "";
            } else
                $xml .= "<" . $key . ">";
        }
        $xml .= "";
        return $xml;
    }
    /**
     * 獲取簽名
     */
    public static function getSign($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;
    }
}

github下載地址：https://github.com/dedemao/we...