Update

app/Services/MessageService.php

@@ -19,19 +19,15 @@ class MessageService
             if ($employee instanceof Employee) {
                 return $employee->id;
             }
-            return $employee;
+            return (int) $employee;
         })->all();
 
-        $message = Message::create([
+        Message::create([
             'type' => $type,
             'title' => $title,
             'content' => $content,
             'additional' => $additional,
             'employee_ids' => $employeeIds,
         ]);
-
-        switch ($message->type) {
-            // @todo 根据消息类型发送通知
-        }
     }
 }