scrollview组件顶部追加新数据时滚动条会直接跳到顶部，而如果在底部追加新数据滚动条不会跳变。想实现类似微信聊天页面向下滑动拉取历史消息，但拉取完历史消息后不要直接跳转到顶部。目前小程序的scrollView会直接跳转到顶部了。 https://developers.weixin.qq.com/s/awlzC9mW7Q5l

根据https://pay.weixin.qq.com/wiki/doc/apiv3/wxpay/pay/combine/chapter3_2.shtml 这个文档,开发合单支付严格按照文档要求进行签名,但是返回的结果始终是如下,按照https://wechatpay-api.gitbook.io/wechatpay-api-v3/chang-jian-wen-ti/qian-ming-xiang-guan 该文档,签名失败也没有提供detail的细节说明. 如下是返回的错误信息,包含header头信息 "HTTP\/1.1 401 Unauthorized\r\nServer: nginx\r\nDate: Sun, 05 Apr 2020 04:27:15 GMT\r\nContent-Type: application\/json; charset=utf-8\r\nContent-Length: 67\r\nConnection: keep-alive\r\nKeep-Alive: timeout=8\r\nCache-Control: no-cache, must-revalidate\r\nX-Content-Type-Options: nosniff\r\nRequest-ID: 2pu3so\r\n\r\n{\"code\":\"SIGN_ERROR\",\"message\":\"验签失败，请检查签名\\t\"}\n" 请问一下 合单下单-JS支付API的 签名是怎样的. 我的签名规则如下 $url = 'https://api.mch.weixin.qq.com/v3/combine-transactions/jsapi';   $timestamp = time();         $nonce = $this->nonce_str();   $datas = json_encode($params);           $sign = $this->sign1($url, 'POST', $timestamp, $nonce, $datas , $this->mch_private_key, $this->mch_id, $this->serial_no);         // echo(mb_strlen(' WECHATPAY2-SHA256-RSA2048 ' . $sign,"utf-8"));         //设置header头         $header = [             'Authorization: WECHATPAY2-SHA256-RSA2048 ' . $sign,             'Accept:application/json',             'User-Agent:' . $this->mch_id,             'Content-Type:application/json',            'Wechatpay-Serial:' . $zhengshu         ]; 签名的函数如下    public function sign1($url, $http_method, $timestamp, $nonce, $bodya, $mch_private_key, $merchant_id, $serial_no)     {                 $url_parts = parse_url($url);         $canonical_url = ($url_parts['path'] . (!empty($url_parts['query']) ? "?${url_parts['query']}" : ""));               $message =             $http_method . "\n" .             $canonical_url . "\n" .             $timestamp . "\n" .             $nonce . "\n" .             $bodya . "\n";         openssl_sign($message, $raw_sign, $mch_private_key, 'sha256WithRSAEncryption');         $sign = base64_encode($raw_sign);         $schema = 'WECHATPAY2-SHA256-RSA2048 ';         $token = sprintf(             'mchid="%s",nonce_str="%s",signature="%s",timestamp="%d",serial_no="%s"',             $merchant_id,             $nonce,             $sign,             $timestamp,             $serial_no,             $bodya         );         // echo($token);         return $token;     } 这个函数也是微信官方文档提供的函数,请教各位大神,怎样解决问题