php微信支付动态金额

<?php
// 假设这是你的微信支付配置
$wechatPayConfig = [
    'appId' => 'your_app_id',
    'mchId' => 'your_mch_id',
    'apiKey' => 'your_api_key',
];

// 假设这是用户选择的商品信息
$userSelectedItems = [
    ['price' => 100, 'quantity' => 2],
    ['price' => 50, 'quantity' => 1],
];

// 计算总金额
$totalAmount = 0;
foreach ($userSelectedItems as $item) {
    $totalAmount += $item['price'] * $item['quantity'];
}

// 生成微信支付订单
$orderId = uniqid();
$notifyUrl = 'https://yourdomain.com/notify'; // 支付回调地址

// 构建支付请求参数
$payParams = [
    'appid' => $wechatPayConfig['appId'],
    'mch_id' => $wechatPayConfig['mchId'],
    'nonce_str' => md5(uniqid()),
    'body' => 'Order ' . $orderId,
    'out_trade_no' => $orderId,
    'total_fee' => $totalAmount * 100, // 金额单位为分
    'spbill_create_ip' => $_SERVER['REMOTE_ADDR'],
    'notify_url' => $notifyUrl,
    'trade_type' => 'JSAPI',
];

// 签名
$payParams['sign'] = generateSign($payParams, $wechatPayConfig['apiKey']);

// 发送支付请求
$response = sendPayRequest($payParams);

// 处理支付响应
if ($response['return_code'] == 'SUCCESS' && $response['result_code'] == 'SUCCESS') {
    // 支付请求成功，跳转到微信支付页面
    header('Location: ' . $response['code_url']);
} else {
    // 支付请求失败，处理错误
    echo '支付请求失败：' . $response['return_msg'];
}

// 生成签名函数
function generateSign($params, $apiKey) {
    ksort($params);
    $str = '';
    foreach ($params as $key => $value) {
        if ($value != '' && $key != 'sign') {
            $str .= "&$key=$value";
        }
    }
    $str .= "&key=$apiKey";
    return strtoupper(md5($str));
}

// 发送支付请求函数
function sendPayRequest($params) {
    $url = 'https://api.mch.weixin.qq.com/pay/unifiedorder';
    $xml = arrayToXml($params);
    $response = postXmlCurl($xml, $url);
    return xmlToArray($response);
}

// 数组转XML函数
function arrayToXml($params) {
    $xml = "<xml>";
    foreach ($params as $key => $value) {
        $xml .= "<$key><![CDATA[$value]]></$key>";
    }
    $xml .= "</xml>";
    return $xml;
}

// 发送XML请求函数
function postXmlCurl($xml, $url) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_POST, 1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, $xml);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);
    $data = curl_exec($ch);
    curl_close($ch);
    return $data;
}

// XML转数组函数
function xmlToArray($xml) {
    libxml_disable_entity_loader(true);
    $array = json_decode(json_encode(simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOCDATA)), true);
    return $array;
}
?>