编写一个应用程序，要求鼠标的光标始终指向一个字符串的起始位置，随着鼠标的移动，字符串跟随移动，而且字符串的颜色在整个字符串中实现渐变。

-Starting position of a string, with the movement of the mouse, the string moves with it, and the color of the string to achieve a gradual throughout the string.