初始化项目：添加后端代码、ThinkPHP框架、前端资源

addons/epay/library/Balance.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace addons\epay\library;
+
+use fast\Http;
+use think\Cache;
+use think\Session;
+use app\common\model\order\Status as OrderStatus;
+use app\common\model\order\Order;
+use app\common\library\Auth;
+use think\Db;
+use app\common\model\User;
+use app\common\exception\Exception;
+/**
+ * 余额
+ *
+ */
+class Balance
+{
+    protected $auth;
+    protected $order;
+    public function __construct()
+    {
+        $this->auth = new Auth();
+        $this->order = new Order();
+    }
+
+    /**
+     * 余额支付
+     * @param $params 订单信息
+     * @return bool
+     */
+    public function pay($order){
+
+        $userInfo = $this->getOrderUser($order['order_no']);
+
+        if(!$userInfo){
+            throw new Exception('获取用户信息失败');
+        }
+
+        //余额不足
+        if($userInfo['money'] < $order['amount']){
+            throw new Exception('余额不足');
+        }
+
+        $order = Db::transaction(function () use ($order,$userInfo) {
+            //扣减余额
+            User::money(($order['amount'] * -1), $userInfo['id'], "余额支付");
+            // 支付后流程
+            $notify = [
+                'order_no' => $order['order_no'],
+                'transaction_id' => '',
+                'notify_time' => date('Y-m-d H:i:s'),
+                'buyer_email' => $userInfo['id'],
+                'pay_fee' => $order['amount'],
+                'pay_type' => 'balance'             // 支付方式
+            ];
+            $notify['payment_json'] = json_encode($notify);
+
+            return Order::paySuccess($order, $notify);
+
+        });
+
+
+        return $order;
+    }
+
+
+    /**
+     * 获取订单用户信息
+     * @param $orderNo
+     * @return false
+     */
+    public function getOrderUser($orderNo)
+    {
+        $orderInfo = Order::orderNoGetOrder($orderNo);
+
+        if(!$orderInfo){
+            return false;
+        }
+
+        $userInfo = $this->auth->getUserinfo($orderInfo['user_id']);
+
+        return $userInfo;
+    }
+}