/**
* 创建md5摘要,规则是:按参数名称a-z排序,遇到空值的参数不参加签名。
*/
private function createSign($parameters,$key) {
$signPars = "";
ksort ( $parameters );
foreach ( $parameters as $k => $v ) {
if ("" != $v && "sign" != $k) {
$signPars .= $k . "=" .urlencode($v) . "&";
}
}
$signPars .= "key=" . $key;
$sign = strtolower ( md5 ( $signPars ) );
return $sign;
}