8.15 颜色拾取器

说明：  本程序实现了图像颜色的拾取，当鼠标点到的地方，在窗体的文本框中就会显示该象素的rgb值以及hsl值
(realized by the color of the images picked up when the mouse to the point where, in the form of text box will show that the pixel value and the rgb values hsl)