给List Box控件添加背景图片,并实现透明-List Box control to add a background image, and to achieve transparent

实现如何回执透明位图，上层位图一共有8个透明部分，透过他们可以清楚的观察到下层的图片-Realize how receipt transparent bitmap, upper bitmap has a total of eight transparent part, through they can clearly observed in the lower picture