C＃ - 当用户点击箭头键时，上下文菜单条具有滚动行为

I have a context menu strip with 8 items and two separators. When the user brings up the context menu strip, then hits the arrow key to scroll through the items, hitting the eighth item causes the menu to 'scroll' up, leaving blank space at the bottom. Is there any way to prevent that behaviour?I have a context menu strip with 8 items and tw