thinkphp6中使用微信支付v3版本

1.引入SDK到项目中
composer require wechatpay/wechatpay-guzzle-middleware
2.引入Guzzle，Guzzle 将使用 PHP 流包装器发送 HTTP 请求
composer require guzzlehttp/guzzle:^7.0
3.在控制器中使用
use GuzzleHttp\Exception\RequestException;
use WechatPay\GuzzleMiddleware\WechatPayMiddleware;
use WechatPay\GuzzleMiddleware\Util\PemUtil;

// 商户相关配置
$merchantId = '1000100'; // 商户号
$merchantSerialNumber = 'XXXXXXXXXX'; // 商户API证书序列号
$merchantPrivateKey = PemUtil::loadPrivateKey('/path/to/mch/private/key.pem'); // 商户私钥
// 微信支付平台配置
$wechatpayCertificate = PemUtil::loadCertificate(app()->getRootPath().'/wechatpay_56E4BDC5960BB32054738D302C1943DD8630FA25.pem'); // 微信支付平台证书文件路径（我放在了项目根目录）

// 构造一个WechatPayMiddleware
$wechatpayMiddleware = WechatPayMiddleware::builder()
    ->withMerchant($merchantId, $merchantSerialNumber, $merchantPrivateKey) // 传入商户相关配置
    ->withWechatPay([ $wechatpayCertificate ]) // 可传入多个微信支付平台证书，参数类型为array
    ->build();

// 将WechatPayMiddleware添加到Guzzle的HandlerStack中
$stack = \GuzzleHttp\HandlerStack::create();
$stack->push($wechatpayMiddleware, 'wechatpay');

// 创建Guzzle HTTP Client时，将HandlerStack传入
$client = new \GuzzleHttp\Client(['handler' => $stack]);


// 创建Guzzle HTTP Client时，将HandlerStack传入，接下来，正常使用Guzzle发起API请求，WechatPayMiddleware会自动地处理签名和验签
$client = new \GuzzleHttp\Client(['handler' => $stack]);
    try {
      $resp = $client->request(
          'POST',
          'https://api.mch.weixin.qq.com/v3/pay/transactions/jsapi', //请求URL
          [
              // JSON请求体
              'json' => [
                  "time_expire" => "2023-03-15T10:34:56+08:00",
                  "amount" => [
                      "total" => 10,
                      "currency" => "CNY",
                  ],
                  "mchid" => "16388714xx",
                  "description" => "测试",
                  "notify_url" => "https://xxx.com/admin/Login/notifyUrlApi",
                  "payer" => [
                      "openid" => "22CBI5G1ILObeNu1oHhGjLI7k2Cs",
                  ],
                  "out_trade_no" => "1217752501201407033233368018",
                  "goods_tag" => "WXG",
                  "appid" => "wx2d5db4945b8537xx",
                  "attach" => "自定义数据说明",
                  "scene_info" => [
                      "store_info" => [
                          "address" => "广东省深圳市南山区科技中一道10000号",
                          "area_code" => "440305",
                          "name" => "腾讯大厦分店",
                          "id" => "0001",
                      ],
                      "device_id" => "013467007045764",
                      "payer_client_ip" => "14.23.150.211",
                  ]
              ],
              'headers' => [ 'Accept' => 'application/json' ]
          ]
      );
   
      $statusCode = $resp->getStatusCode();
      if ($statusCode == 200) { //处理成功
          echo "success,return body = " . $resp->getBody()."\n";
      } else if ($statusCode == 204) { //处理成功，无返回Body
          echo "success";
      }
  } catch (RequestException $e) {
      // 进行错误处理
      echo $e->getMessage()."\n";
      if ($e->hasResponse()) {
          echo "failed,resp code = " . $e->getResponse()->getStatusCode() . " return body = " . $e->getResponse()->getBody() . "\n";
      }
      return;
  }

注意！！！：上面代码中配置证书不是商户公钥，一定要记住！！！下面是此配置讲解
// 微信支付平台配置
$wechatpayCertificate = PemUtil::loadCertificate('/path/to/wechatpay/cert.pem'); // 微信支付平台证书
微信支付平台证书 获取方式：
composer exec CertificateDownloader.php -- -k ${apiV3key} -m ${mchId} -f ${mchPrivateKeyFilePath} -s ${mchSerialNo} -o ${outputFilePath}

Options:
  -m, --mchid=<merchantId>   商户号
  -s, --serialno=<serialNo>  商户证书的序列号
  -f, --privatekey=<privateKeyFilePath>
                             商户的私钥文件
  -k, --key=<apiV3key>       ApiV3Key
  -o, --output=[outputFilePath]
                             下载成功后保存证书的路径，可选参数，默认为临时文件目录夹
  -u, --baseuri=[baseUri]    接入点，默认为 https://api.mch.weixin.qq.com/
  -V, --version              Print version information and exit.
  -h, --help                 Show this help message and exit.

例如：composer exec CertificateDownloader.php -- -k 123456789098765432116606169225 -m 1638871484 -f file:///www/wwwroot/daidai.qhwoyoung.com/apiclient_key.pem -s 7823EA0FFC9160F49C21F61ED277FC0A7A78410C -o file:///www/wwwroot/daidai.qhwoyoung.com/