Question

我正在尝试创建一个菜单，我需要打开一个JPanel。我怎样才能做到这一点？

我希望用户按“个人详细信息”为例，然后打开一个可以添加按钮和文本字段的区域。

public class Payroll{

public static void main(String[] args) {
    JFrame frame = new JFrame(" Payroll "); 

    //create the employees details menu 
    JMenu employees = new JMenu("Employees");
    employees.setMnemonic(KeyEvent.VK_E);

    // add employees items
        JMenuItem details = new JMenuItem("Individual Details");
        details.addActionListener(new ActionListener( )
        {
            public void actionPerformed(ActionEvent e)
            { 
                /**********missing code is here, how can i open a JPanel from here?**/ 

            }
        });

        employees.add(details);


    //menu bar 
    JMenuBar menuBar = new JMenuBar( ); 
    menuBar.add(employees);


    frame.setJMenuBar(menuBar);
    frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
    frame.setSize(700,550);
    frame.setVisible(true);

} 

}

Answer 1

您可以创建另一个具有jpanel的类和用于获取userinput的字段。然后在menuitem actionPerformed事件中创建它的实例...

例如

;

这是具有面板的类

import java.awt.GridLayout;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class MyPanel {

    public MyPanel() {
        JFrame f=new JFrame();
        f.setSize(300,200);
        f.setLayout(new GridLayout(1, 1));
        JPanel p=new JPanel();
        p.setLayout(new GridLayout(3, 1, 2, 2));
        JTextField t1=new JTextField(20);
        p.add(t1);
        f.add(p);
        f.setVisible(true);
    }


}

并在事件中创建它的实例..

public class Payroll{

public static void main(String[] args) {
    JFrame frame = new JFrame(" Payroll "); 

    JMenu employees = new JMenu("Employees");
    employees.setMnemonic(KeyEvent.VK_E);

    // add employees items
        JMenuItem details = new JMenuItem("Individual Details");
        details.addActionListener(new ActionListener( )
        {
            public void actionPerformed(ActionEvent e)
            { 
                MyPanel panel=new MyPanel(); // call MyPanel here

            }
        });

        employees.add(details);


    //menu bar 
    JMenuBar menuBar = new JMenuBar( ); 
    menuBar.add(employees);


    frame.setJMenuBar(menuBar);
    frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
    frame.setSize(700,550);
    frame.setVisible(true);

} 

}

Answer 2

您可以尝试如下，

JPanel panel = new JPanel();
JButton okButton = new JButton("OK");
panel.add(okButton);
JButton cancelButton = new JButton("Cancel");
panel.add(cancelButton);
frame.add(panel);

如何从菜单中打开JPanel？

2 个答案: