难点是请求https://api.weixin.qq.com/wxa/getwxacodeunlimit ，
的时候请求方式是raw，第二，由于返回的是图片的数据，因此，直接把返回的数据写进文件中就可以。
$appid = '';//$secret='';$sendurl="https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$appid."&secret=".$secret;$return =$this-http_get($sendurl1) ;$data=json_decode($return,true);$pic=$this-http_postraw("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=".$data['access_token'],$user['id']) ;$jpg = 'D://WWW/eschool/imgpublic/wxappshare_'.$data1['unionId'].'.jpg'; ob_end_clean();//清空缓冲区$fp = fopen($jpg,'w');//写入图片if(fwrite($fp,$pic)){ fclose($fp);}/*** POST 请求* @param string $url* @param array $param*/private function http_postraw($url,$param){$curl = curl_init();if(stripos($url,"https://")!==FALSE){curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);curl_setopt($curl, CURLOPT_SSLVERSION, 1); //CURL_SSLVERSION_TLSv1}curl_setopt_array($curl, array(CURLOPT_URL = $url,CURLOPT_RETURNTRANSFER = true,CURLOPT_ENCODING = "",CURLOPT_MAXREDIRS = 10,CURLOPT_TIMEOUT = 30,CURLOPT_HTTP_VERSION = CURL_HTTP_VERSION_1_1,CURLOPT_CUSTOMREQUEST = "POST", CURLOPT_POSTFIELDS = "{t"page":"pages/index/index",t"scene":"".$param."",t"width":"280"}",CURLOPT_HTTPHEADER = array("Content-Type: application/json","cache-control: no-cache"),));$response = curl_exec($curl);$err = curl_error($curl);curl_close($curl);if ($err) { return("cURL Error #:" . $err);} else { return($response) ;}}
