SetWindowLong
http://msdn.microsoft.com/en-us/library/windows/desktop/ms633591(v=vs.85).aspx
Window Styles
http://msdn.microsoft.com/en-us/library/windows/desktop/ms632600(v=vs.85).aspx
Extended Window Styles
http://msdn.microsoft.com/en-us/library/windows/desktop/ff700543(v=vs.85).aspx
Window Features
http://msdn.microsoft.com/en-us/library/windows/desktop/ms632599(v=vs.85).aspx#layered
一旦 Form 被定义为利用 LayeredWindow ,窗口的绘图不再响应沿用多年的 WM_Paint 消息。
http://www.360doc.com/content/11/0424/15/5131150_111970536.shtml