在ComponentListener中传递2个对象和这些对象

Question

void NewJDialogcallone(JFrame frame) 
{
    location = frame.getLocationOnScreen();
    int x = location.x;
    int y = location.y;
    dialog.setLocation(x, y);
    dialog.setLocationRelativeTo(frame);
    dialog.setVisible(true);
    dialog.setAlwaysOnTop(true);
    dialog.addComponentListener(this);
}

public void componentMoved(ComponentEvent e,?????) 
{
    JOptionPane.showConfirmDialog (null,
                                "This is the \"Ok/Cancel\"message dialog box.",
                                "",
                                JOptionPane.OK_CANCEL_OPTION);
}

我想使用frame对象，这样对话框就可以相对于父frame移动。我移动父框架，对话框也随之移动。我想调用dialog.setLocationRelativeTo(//parent frame object//)，只有在拥有父框架对象时才能调用。

如果有任何方法可以获得这种窗口行为，请帮助我。

Answer 1

您只需要在方法参数JFrame frame前面添加关键字final即可。

 void NewJDialogcallone(final JFrame frame) 
 ...

我还建议避免使用以下代码：

dialog.setAlwaysOnTop(true);

因为它对用户体验真的很烦人。通常，这是你没有正确实例化你的对话框的标志，例如，通过传递正确的Frame/Dialog所有者。

下面是一个不使用setAlwayOnTop()的窗口位置同步示例：

import java.awt.Point;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;

import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;

public class Test {

    protected void initUI() {
        final JFrame frame = new JFrame();
        frame.setTitle("Test dialog synch");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            // On the next line I pass "frame" to the dialog so that the dialog never
            // goes behind the frame, avoiding the need for setAlwaysOnTop
        final JDialog dialog = new JDialog(frame, false);
        dialog.setSize(200, 50);
        frame.addComponentListener(new ComponentAdapter() {

            private Point lastLocation;

            @Override
            public void componentMoved(ComponentEvent e) {
                if (lastLocation == null && frame.isVisible()) {
                    lastLocation = frame.getLocation();
                } else {
                    Point newLocation = frame.getLocation();
                    int dx = newLocation.x - lastLocation.x;
                    int dy = newLocation.y - lastLocation.y;
                    dialog.setLocation(dialog.getX() + dx, dialog.getY() + dy);
                    lastLocation = newLocation;
                }
            }

        });
        frame.setSize(400, 200);
        frame.setVisible(true);
        dialog.setLocationRelativeTo(frame);
        dialog.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new Test().initUI();
            }
        });
    }

}

Answer 2

您可以轻松地创建组件侦听器，该侦听器引用所需的任何对象

    final Object one = new Object();
    final Object two = new Object();

    ComponentListener listener = new ComponentListener() {
        public void componentHidden(ComponentEvent e) {
            one.toString();
        }
        public void componentMoved(ComponentEvent e) {
            two.toString();
        }
        public void componentResized(ComponentEvent e) {
            one.toString();
        }
        public void componentShown(ComponentEvent e) {
            two.toString();
        }
    };