feat：修复签名

@@ -80,14 +80,23 @@ class Api
     {
         $recv_window = '5000';
         $queryString = '';
+        $postBody = '';
 
         if ($method == 'GET' && !empty($params)) {
+            ksort($params);
             $queryString = http_build_query($params);
         }
-
-        $sign_str = $timestamp . $this->apiInfo->key . $recv_window . $path . $queryString;
         if ($method == 'POST' && !empty($params)) {
-            $sign_str .= json_encode($params);
+            ksort($params);
+            $postBody = json_encode($params);
+        }
+
+        $sign_str = $timestamp . $this->apiInfo->key . $recv_window . $path;
+        if ($queryString) {
+            $sign_str .= '?' . $queryString;
+        }
+        if ($postBody) {
+            $sign_str .= $postBody;
         }
 
         return hash_hmac('sha256', $sign_str, $this->apiInfo->secret);