示例#1
0
文件: DB.php 项目: scorp7mix/ppp
 public static function getInstance()
 {
     if (empty(self::$instance)) {
         self::$instance = new self();
     }
     return self::$instance;
 }
示例#2
0
 public static function getInstance()
 {
     //判断self::$instance 是否已经被实例化
     if (!self::$instance instanceof self) {
         self::$instance = new self();
     }
     return self::$instance;
 }
示例#3
0
文件: Db.php 项目: romanovvv1987/mvc
 public final function __destruct()
 {
     self::$instance = null;
 }