Netbeans Bean Form

Question

Hi,
I created a class (MyPanel) using the JPanel Form.
I added some Component (JButton, TextField..)
I added it under Bean the Palette Manager so I can reuse it.
I created a class (MyCustomPanel) using the Bean Form and deriving from MyPanel.
I got the following error:
Error in loading component: [MyPanel]
Failed to initialize layout of this container.
MyPanel is working perfectly fine if I add it to another JPanel instead of inheriting from it.
So my questions are:
How to use the Bean Form?
Am I using it as it is meant to?
Is the Bean Form what I should use to derive from a panel and be able to use the Design view
What could be causing the error with the layout?
Thank you.

Answer 1

To make it a Bean, you must implement java.io.Serializable, and add getXXX and setXXX methods for your private variable foobar. As a bean, the code you've provided would look kinda like this:
class SampleJCB
      extends JComboBox
            implements Serializable {
    private int foobar = 0;
    public SampleJCB() {
        super();
        foobar = 15;
    public int getFoobar(){
        return foobar;
    public void setFoobar(int foobar) {
        this.foobar = foobar;
}Now, if you're interested in persistance of you're ComboBox, you may want to check out the Serializable Fields API, which will give you the details on how to serialize objects, how to write readObject and writeObject methods, how to define which fields are default serializable, etc.
Another thing you should note is that all swing components are already beans. So, JComboBox is itself a bean, and hence, when you create a subclass of JComboBox, it is, in a way, already a bean.