DesktopManager.openFrame(JInternalFrame f) has the following syntax.
void openFrame(JInternalFrame f)
In the following code shows how to use DesktopManager.openFrame(JInternalFrame f) method.
//from ww w . j a v a 2s. c o m import java.awt.BorderLayout; import javax.swing.JDesktopPane; import javax.swing.JFrame; import javax.swing.JInternalFrame; import javax.swing.JLabel; public class Main { public static void main(final String[] args) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JDesktopPane desktop = new JDesktopPane(); JInternalFrame internalFrame = new JInternalFrame("Can Do All", true, true, true, true); desktop.add(internalFrame); internalFrame.setBounds(25, 25, 200, 100); JLabel label = new JLabel(internalFrame.getTitle(), JLabel.CENTER); internalFrame.add(label, BorderLayout.CENTER); internalFrame.setVisible(true); desktop.getDesktopManager().openFrame(internalFrame); frame.add(desktop, BorderLayout.CENTER); frame.setSize(500, 300); frame.setVisible(true); } }