一个可以居中、排列填充、拉伸主图、并且允许有N多个辅助图象，辅助图象可以透明背景，该控件做程序主背景比较好，自己写的。-a middling, and arranged to fill the tensile main map, and allow more than N auxiliary image, Supplementary images can be transparent background, the main control procedures do better backgr