tp pc,m 在共用一个框架的情况下，共用模型

/** * D函数用于实例化Model 格式 项目://分组/模块 * @param string $name Model资源地址 * @param string $layer 业务层名称 * @return Model */function D($name='',$layer='') {if(empty($name)) return new Model;    static $_model  =   array();    $layer          =   $layer?$layer:C('DEFAULT_M_LAYER');$name       =   '/openapi/Lib/'.$layer.'/'.$name;    if(isset($_model[$name]))   return $_model[$name];    import($name.$layer);    $class          =   basename($name.$layer);    if(class_exists($class)) {        $model      =   new $class();    }else {        $model      =   new Model(basename($name));    }    $_model[$name]  =  $model;    return $model;}