改进Model类的__isset方法

library/think/Model.php

@@ -1294,13 +1294,18 @@ abstract class Model implements \JsonSerializable, \ArrayAccess
      */
     public function __isset($name)
     {
-        if (array_key_exists($name, $this->data)) {
+        try {
-            return true;
+            if (array_key_exists($name, $this->data)) {
-        } elseif ($this->getAttr($name)) {
+                return true;
-            return true;
+            } elseif ($this->getAttr($name)) {
-        } else {
+                return true;
+            } else {
+                return false;
+            }
+        } catch (InvalidArgumentException $e) {
             return false;
         }
+
     }
 
     /**