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Hi ,
I am totally new to java and exploring the Swing class concepts with the help of the below program.Basically add a panel to a frame.
package uicontrols;
import java.awt.*;
import javax.swing.*;
//import javax.swing.JPanel;
public class JPanel extends JFrame
{
JPanel obj2;
JFrame obj1;
public initialize()
{
obj1 = new JFrame();
setTitle("FrameDemo");
setVisible(true);
setSize(300, 300);
obj2 = new JPanel();
obj2.setTitle("PanelDemo");
obj2.setVisible(true);
obj2.setSize(300, 100);
obj1.add(obj2);
}
public static void main(String[] args) {
JPanel jp = new JPanel();
jp.initialize();
}}
The program runs and show me a Frame Window and on top of it a Panel but gives the below errors as well.Can some pleas help me understand the cause of these errors.
Thanks in advance.
Exception in thread "main" java.lang.IllegalArgumentException: adding a window to a container
at java.awt.Container.checkNotAWindow(Container.java:490)
at java.awt.Container.addImpl(Container.java:1091)
at java.awt.Container.add(Container.java:1005)
at javax.swing.JFrame.addImpl(JFrame.java:567)
at java.awt.Container.add(Container.java:417)
at uicontrols.JPanel.initialize(JPanel.java:24)
at uicontrols.JPanel.main(JPanel.java:30)