在添加新的JPanel之前如何从JFrame删除JPanel

Question

I have JPanel has already added to JFrame. And I have dynamically added JPanel. After adding JPanel on the fly it stay near the JPanel added before. How can I delete previous JPanel?

PS I also think about using cardlayout - is it a good way?

Answer 1

There is a method getComponents() which will give you the child component in JFrame

you will use it like this way:

Component[] comp = frame.getContentPane().getComponents();
for(int i=0; i<comp.lenght; i++)
{
    if(comp[i] instanceof JPanel)
    {
        frame.remove(comp[i]);
    }
}

Note: this fix only works when you have single JPanel inside JFrame at a time, otherwise you gonna remove all your JPanels from JFrame .