问题
How can I set a quite large drag icon made by transparent dragging component image. So the user sees what has selected for dragging while dragging.
It'd better that the image has a graded transparent level so the bottom right of the component image will be 99% transparent and the top left of the componenet image will have 50% transparency. What I need is generating the image and converting it to an ImageIcon.
The component can be any thing. Even a complex one. For example a JPanel with some other components inside.
来源：https://stackoverflow.com/questions/20831078/transparent-dragging-component-image-as-the-drag-icon-in-swing