IE Transparency Hack Internet Explorer has flawed PNG handling, meaning that alpha-transparent PNGs have a flat grey background. Fortunately there is a way to fix this - by applying a DirectX filter to PNG images. If you want further details about t

在一个论坛中已注册用户和游客的权限不同，已注册的用户拥有发帖、修改自己的注册信息、修改自己的帖子等功能；而游客只能看到别人发的帖子，没有其他权限。使用代理模式来设计该权限管理模块。