VC++非矩形窗体（四角为弧形）的代码实例，像一些音乐播放器的窗体、一些游戏的窗体等，除了把角变为弧形外，还有圆角、椭圆窗体和不规则窗体，我的实现过程是设置对话框的背景为 “TRANSPARENT”（透明），并在WM_CTLCOLORDLG消息处理器中创建一支“空笔”（NULL）来绘制对话框背景，然后用TransparenBlt将自己的位图放到对话框上。

-VC++ non-rectangular form (four corners of the arc) of the code examples, like some form music player, some games and other forms, in addition to angle into a curved, there are rounded corners, oval form and not Rules of the form, I realize the process is to set the dialog background " TRANSPARENT"　(transparent), and the message processor WM_CTLCOLORDLG create a " space pen"　(NULL) to draw the background of the dialog box, and then TransparenBlt itself the bitmap into the dialog box.