直接以ColorSelectionModel的addChangeListener()方法来检测用户是否对颜色的选择有所改变。每当用户在JColorChooser上做一次颜色的改变时，就会触发ChangeEvent事件，因此我们必须实现ChangeListener界面来处理这个事件。-directly to the addChangeList ColorSelectionModel ener () method to detect whether users choose the right color change. Whenever users JColorChooser done a color change, ChangeEvent will trigger events, Therefore, we must realize ChangeListener interface to handle this incident.