为什么这里没有出现“绘图”？我将它添加到另一个 JPanel，然后将所有内容添加到另一个 JPanel 并返回。然而，我看到的只是轨迹球
public class Draw extends JFrame
{
private JSplitPane itemPane;
private Point position = null;
public Draw()
{
// Set the layout to a grid
setLayout ( new BorderLayout (5,5));
// Set the properties of the window
setTitle ("Emulator");
setSize ( 900, 700);
setDefaultCloseOperation (EXIT_ON_CLOSE);
setBackground ( new Color (15, 255, 10));
// Add the components
addComponents ();
}
public static void startWindowsGui()
{
// We are in the static main, set the form to invoke later
SwingUtilities.invokeLater ( new Runnable()
{
public void run()
{
// Create a new instance of server and set it to visible
Draw gui = new Draw();
gui.setVisible (true);
}
} );
}
private void addComponents()
{
// Create the main and an itemPane
JSplitPane mainPane = new JSplitPane ( JSplitPane.HORIZONTAL_SPLIT );
setItemPane(new JSplitPane ( JSplitPane.VERTICAL_SPLIT ));
mainPane.add ( createPane ( ), JSplitPane.LEFT );
mainPane.add ( getItemPane(), JSplitPane.RIGHT );
mainPane.setOneTouchExpandable ( true );
getItemPane().setOpaque(true);
getItemPane().setBackground(new Color(0xffffffc0));
JPanel p = new JPanel();
this.getItemPane().add(p);
add ( mainPane, BorderLayout.CENTER );
}
public static void main(final String[] args)
{
Runnable gui = new Runnable()
{
@Override
public void run()
{
new Draw().setVisible(true);
}
};
SwingUtilities.invokeLater(gui);
}
private class Drawing extends JPanel {
private static final long serialVersionUID = 1L;
private final Point position;
public Drawing(Point position) {
this.position = position;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(Color.RED);
g2.fillOval(160 + position.x, 160 - position.y, 15, 15);
}
}
private JPanel createPane()
{
// Create the feedPanel
JPanel panel = new JPanel ( );
JPanel panel2 = new JPanel ( );
JPanel panel3 = new JPanel ( );
this.position = new Point();
TrackBall myJoystick = new TrackBall(150, position, 100);
panel.add(myJoystick, BorderLayout.PAGE_END);
Drawing drawing = new Drawing(position);
panel2.add(drawing, BorderLayout.PAGE_START);
panel3.add(panel2);
panel3.add(panel);
return panel3;
}
public JSplitPane getItemPane() {return itemPane;}
public void setItemPane(JSplitPane itemPane) {this.itemPane = itemPane;}
}