以圣诞为背景，设计一个分别以26个大写字母为内容的26个命令按钮，在窗体中循环闪烁。窗体中有开始，暂停，清空，关闭按钮控件-Background of Christmas, 26 of the 26 uppercase letters for content design a command button, flash cycle in the form. Form, start, pause, clear, close button controls