If your dropdowns are this long, you might wanna take a re-look at your navigational strategy. But, if it makes sense, a technique like this may be beneficial.
PROBLEM: Dropdown menu goes down below the fold when opened, making lower items inaccesible.
SOLUTION? Make menu scroll up and down as you mouse through it.
代码整理：时代Java（NowJava.com）
转载请注明出处，此代码仅供学习交流，请勿用于商业用途。