Question

我在两个不同的面板中添加了两个按钮，如果单击第一个按钮，则需要使用第二个按钮进入下一个面板。但是当我点击第一个按钮时，按钮没有被替换。

/*Java GUI*/

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;


public class TestFrame extends JFrame{

    private JPanel panel1, panel2;
    private JButton but,but2; 

    public TestFrame()
    {
        createPanel();
        addPanel();
    }

    private void createPanel()
    {
        panel1 = new JPanel();
        but = new JButton("TestButton");
        but.addActionListener(new addButtonListener());

        panel2 = new JPanel();
        but2 = new JButton("TestButton2");

    }

    private void addPanel()
    {
        panel1.add(but);
        panel2.add(but2);

        add(panel1);

    }

    class addButtonListener implements ActionListener
    {
        public void actionPerformed(ActionEvent ae) 
        {
            getContentPane().removeAll();
            add(panel2);

            repaint();
        }
    }


    public static void main(String args[])
    {
        JFrame frame = new TestFrame();
        frame.setTitle("Test Software");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(500,500);

        frame.setVisible(true);
    }



}

Answer 1

您需要进行验证然后重新绘制。

validate();
repaint();

Answer 2

从contentPane中重新启动所有内容后，尝试将面板添加到ContentPane。第二件事是重新粉刷。如果您不更新面板内容，则会在调整大小后进行绘制。在这里，您是示例解决方案：



    import java.awt.event.ActionEvent;

    import java.awt.event.ActionListener;

    import javax.swing.*;

    public class Frame extends JFrame{
        private JPanel panel1, panel2;
        private JButton but,but2; 
        public Frame()
        {
           createPanel();
           addPanel();
        }
        private void createPanel()
        {
            panel1 = new JPanel();
            but = new JButton("TestButton");
            but.addActionListener(new addButtonListener());
            but.setBounds(50, 90, 190, 30);//There are example values but remember about setting size
            panel2 = new JPanel();
            but2 = new JButton("TestButton2");
            but2.setBounds(50, 50, 90, 30);//There are example values but remember about setting size
        }
        private void addPanel()
        {
            panel1.add(but);
            panel2.add(but2);
            add(panel1);
        }

        class addButtonListener implements ActionListener
        {
            public void actionPerformed(ActionEvent ae) 
            {
                getContentPane().removeAll();
                getContentPane().add(panel2);//Adding to content pane, not to Frame
                repaint();
                printAll(getGraphics());//Extort print all content
            }
        }

        public static void main(String args[])
        {
            Frame frame = new Frame();
            frame.setTitle("Test Software");
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setSize(500,500);
            frame.setVisible(true);
        }

    }

Oracle文档解释了直接添加到contentPane或Frame的差异beetwen http://docs.oracle.com/javase/tutorial/uiswing/components/toplevel.html

Java GUI，根据actionListener更改面板

2 个答案: