update

app/appfront/config/modules/Checkout.php

@@ -17,7 +17,7 @@ return [
          * 模块内部的params配置。
          */
         'params'=> [
-
+            'guestOrder' => false, // 是否支持游客下单
         ],
     ],
 ];

app/appfront/modules/Checkout/controllers/OnepageController.php

@@ -27,8 +27,12 @@ class OnepageController extends AppfrontController
 
     public function actionIndex()
     {
-        //var_dump(Yii::$app->request->post());
-
+        $guestOrder = Yii::$app->controller->module->params['guestOrder'];
+        if(!$guestOrder && Yii::$app->user->isGuest){
+            $checkoutOrderUrl = Yii::$service->url->getUrl('checkout/onepage/index');
+            Yii::$service->customer->setLoginSuccessRedirectUrl($checkoutOrderUrl);
+            return Yii::$service->url->redirectByUrlKey('customer/account/login');
+        }
         $_csrf = Yii::$app->request->post('_csrf');
         if ($_csrf) {
             $status = $this->getBlock('placeorder')->getLastData();

services/payment/Paypal.php

@@ -176,7 +176,7 @@ class Paypal extends Service
      */
     protected function isNotDuplicate()
     {
-        $ipn = $this->_ipnMessageModel::find()
+        $ipn = $this->_ipnMessageModel->find()
             ->asArray()
             ->where([
             'txn_id'=>$this->_postData['txn_id'],