如何从jpanel中提取信息

Question

I am trying a project called white board sharing in which I need to get the information from a panel and that information is like some drawings so how can I get it from a panel. In that panel I am drawing some rectangles circles.

Answer 1

In case you want to react on mouse events you might want to investigate the following sections of the Java API.

MouseListener

MouseMotionListener

Also if you want to react on mouse events that are triggered when the users moves his mouse over a drawn element you might be interested in Graphics2D and the classes that implement Shape .

Answer 2

您可以将Graphics对象传递给面板以绘制所绘制的项目。

Answer 3

It may help to think of the board as a view of some model that records an abstract representation of the board's content. As a concrete example, this GraphPanel has a very simple model containing nothing more than a List<Node> and a List<Edge> . These two members could be wrapped and serialized as discussed in this tutorial .