从上向下，从下向上，从左到右，从右到左4种方式打开BMP图像。效果明显。仔细观察打开过程中的线条涌动会是一件很有趣的事。-From the top down, from the bottom up, from left to right, right to left, four ways to open the BMP image. The effect is obvious. Carefully observe the surging lines open process will be a