edit

lib/Wechat.php

@@ -122,6 +122,7 @@ class Wechat extends Core
 			$string['timestamp'] = $order['time'];
 			ksort($string);
 			$string = str_replace('%3D', '=', http_build_query($string));
+			$string .= '&key=' . $this->config->GetKey();
 			$this->log('支付签名-app', $string);
 			if($order['sign_type'] == "MD5"){
 				$string = md5($string);