初始化项目：添加后端代码、ThinkPHP框架、前端资源

addons/epay/library/Response.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace addons\epay\library;
+
+class Response extends \Symfony\Component\HttpFoundation\Response implements \JsonSerializable, \Serializable
+{
+    public function __toString()
+    {
+        return $this->getContent();
+    }
+
+    public function jsonSerialize()
+    {
+        return $this->getContent();
+    }
+
+    public function serialize()
+    {
+        return serialize($this->content);
+    }
+
+    public function unserialize($serialized)
+    {
+        return $this->content = unserialize($serialized);
+    }
+}