如何处理JPanel-jPanel1.dispose（）或等效方法

Question

How can we dispose() a JPanel?

I've done jPanel1.removeAll() and now I want JPanel to be disposed so that jPanelParent.getComponents() can't return it

Component[] components = this.jPanelParent.getComponents();  /// Returns 5 Components      
JPanel last = (JPanel)components[components.length];
last.removeAll();
//last.dispose()   NOT AVAILABLE

Now after above code if I run .getComponents() I don't want to get "last" in above code

Answer 1

This is a classic case of looking in the wrong place for an answer; your question presupposes a way to do things, and you ask how to do that presupposed and erroneous operation, and confusion ensues. It doesn't help that "dispose" is a term used for an operation you don't need at all, having to do with making memory available for reclaiming in an environment where programmers do these things.

I believe what you want to do is remove the reference that the parent component has to the JPanel. That would fit your desire that getComponents() in the parent panel not return the panel you are getting rid of.

In order for the panel that you are removing to do this, it needs a reference to the parent panel, and then you can remove it from the parent panel just like you've removed components from the target panel. In fact, if the parent panel is the only place that references the target, and the target's components are only referenced in the target, you don't have to remove the target components if you just remove the parent panel reference to the target.

So pass a reference to your parent panel to your target panel, and do a remove() of the target panel from the parent panel in place of your hypothesized dispose() call.

Answer 2

Dispose em JPanel Netbeans java

   Component comp = SwingUtilities.getRoot(this);
   ((Window) comp).dispose();

Answer 3

In my case, my one panel was on a JDialog, and the following can work:

public void dispose() {
    JFrame parent = (JFrame) this.getTopLevelAncestor();
    parent.dispose();
}

However, I think explicitly keeping a reference to the parent in the panel might be a less error prone way, as described in another answer.