/**
* 生成用于回复的数据
*
* @return array
*/
public function buildForReply()
{
if (!method_exists($this, 'toReply')) {
throw new \Exception(__CLASS__ . '未实现此方法：toReply()');
}
$base = array('ToUserName' => $this->to, 'FromUserName' => $this->from, 'CreateTime' => time(), 'MsgType' => $this->getDefaultMessageType());
return XML::build(array_merge($base, $this->toReply()));
}
/**
* 将公众平台回复用户的消息加密打包.
* <ol>
* <li>对要发送的消息进行AES-CBC加密</li>
* <li>生成安全签名</li>
* <li>将消息密文和安全签名打包成xml格式</li>
* </ol>
*
* @param string $xml 公众平台待回复用户的消息，xml格式的字符串
* @param string $nonce 随机串，可以自己生成，也可以用URL参数的nonce
* @param int $timestamp 时间戳，可以自己生成，也可以用URL参数的timestamp
*
* @return string 加密后的可以直接回复用户的密文，包括msg_signature, timestamp,
* nonce, encrypt的xml格式的字符串
*/
public function encryptMsg($xml, $nonce = null, $timestamp = null)
{
$encrypt = $this->encrypt($xml, $this->appId);
!is_null($nonce) || ($nonce = substr($this->appId, 0, 10));
!is_null($timestamp) || ($timestamp = time());
//生成安全签名
$signature = $this->getSHA1($this->token, $timestamp, $nonce, $encrypt);
$response = array('Encrypt' => $encrypt, 'MsgSignature' => $signature, 'TimeStamp' => $timestamp, 'Nonce' => $nonce);
//生成响应xml
return XML::build($response);
}