use super.paintComponent(g) or getGraphics() in java

Question

i\' m little bit confused about few things:

Example code,that shows my problem,this isn\'t compilable

// image
private Buf         


        

Answer 1

There are many questions about "good" or "correct" painting in Swing, so this question could be considered as a duplicate, and I won't try to repeat here what should be read in context, for example, in the Lesson about Performing Custom Painting.

However, to summarize the most important information short and concisely:

• You should never call getGraphics on a Component. It may return null or a Graphics object that is in any other way "invalid". It will fail in the one form or the other, sooner or later
• You should do all your painting operations in the paintComponent method (or in methods that are called from paintComponent), using the Graphics object that you receive there as an argument
• Whether or not you call the Graphics#dispose method may not make a difference that is "immediately" visible. You should not call it on the one that you received in the paintComponent. You should only call it on a Graphics object that you either obtained from a BufferedImage, or one that you created by calling Graphics#create(). When you do not call it, this might cause a memory leak that will only be noticed after the application has been running for a while.