sendClond如何更新邮件模板

         $url = 'http://www.sendcloud.net/webapi/template.update.json';

         $API_USER = '';
         $API_KEY = '';

         $content = "hello  world";//需要替换的html内容

         $param = array(
             'api_user' => $API_USER, # 使用api_user和api_key进行验证
             'api_key' => $API_KEY,
             'invoke_name' => 'talk',
             'html'   => $content,
         );

         $data = http_build_query($param);

         $options = array(
             'http' => array(
                 'method' => 'POST',
                 'header' => 'Content-Type: application/x-www-form-urlencoded',
                 'content' => $data
         ));
         $context  = stream_context_create($options);
         $result = file_get_contents($url, FILE_TEXT, $context);
         echo $result;

之前使用curl方法一直报错,这个才是对的